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Published by fastpolyu2, 2019-01-01 22:58:24

Research at FAST 2018

Research at FAST 2018

Research Overview Department of Applied Mathematics

Prof. Qi has published more than 310 research papers in international journals. He established the superlinear and quadratic
convergence theory of the semismooth Newton method. According to the authoritative citation database www.isihighlycited.com
in 2003, he was one of the world’s most highly cited 345 mathematicians then. In 2005, Prof. Qi pioneered the research
on eigenvalues for higher order tensors, which now has applications in biomedical engineering, statistical data analysis,
spectral hypergraph theory, solid mechanics, quantum mechanics, etc. His books “Tensor Analysis: Spectral Theory
and Special Tensors’’ and “Tensor Eigenvalues and Their Applications’’ were published by SIAM and Springer in 2017 and 2018
respectively.

Spectral Hypergraph Theory via Tensors GRF Project (2014-2017)

Spectral graph theory is a well-studied and highly applicable subject. On the other hand, spectral hypergraph theory is still in its
early stage. In this project, we give the tensor approach for spectral hypergraph theory a clear start. We apply the theory and
computation of eigenvalues of tensors to spectral hypergraph theory. We give a natural and simple definition of the Laplacian and
signless Laplacian tensors, and connected them with the adjacency tensor closely. We use eigenvalues (H-eigenvalues) in the
study of spectral hypergraph theory and justify this approach.

Positive Semi-Definite Symmetric Tensors, Hankel Tensors, Toeplitz Tensors and M-Tensors:
Theory and Algorithms GRF Project (2015-2018)

In this project, we aim to make an extensive study on four important classes of structured tensors, namely positive semi
definite symmetric tensors, Hankel tensors, Toeplitz tensors (including circulant tensors) and M-tensors, for both theory
and algorithms. These four classes of structured tensors naturally arise from applications. Positive semi-definite symmetric
tensors have applications in automatical control and higher order diffusion tensor imaging. Hankel tensors arise in the
context of the harmonic retrieval problem, which is at the heart of many signal processing applications. Toepliz tensors
naturally arise in signal processing methods involving higher-order statistics. Laplacian tensors of uniform hypergraphs are
symmetric M- tensors.

Completely Positive, Completely Decomposable, SOS, Cauchy, Hilbert, P and B Tensors:
Theory and Computation GRF Project (2016-2018)

In this project, we aim to make an extensive study on seven important classes of structured tensors, namely completely positive,
completely decomposable, SOS (sum-of-squares), Cauchy, Hilbert, P and B tensors, where completely decomposable tensors
are first proposed in this project. We study their properties and relations among these tensor classes.

Spectral Theory of Tensors

Leinepar algrebtramandemnatrtix toheofry Ahavpe lopnglbieend fund Mameanttalhtooelsmin mathteimcatsical disciplines. The
modern developments of science and technology, in particular, big data analysis, make matrices not enough. Thus, hypermatrices,
or tensors, arise. The elements of a matrix have two indices. The elements of a hypermatrix have more than two indices. Matrix
theory is linear, while hypermatrix or tensor theory is multilinear. This corresponds the development from two-way data analysis
to multi-way data analysis. Tensor decomposition, tensor approximation and tensor completion, etc., have been developed.
In 2005, in the selected publication 5, I introduced eigenvalues and eigenvectors for higher order tensors. Based upon the
eigenvalues I introduced, the Perron-Frobenius theory of nonnegative matrices was successfully extended to nonnegative
tensors. In 2009, in the selected publication 4, two co-authors and I proposed the first algorithm for computing the largest
eigenvalues of a nonnegative tensor. Then, in a series of papers, other researchers and I identified several easily
checkable subclasses of positive semi-definite tensors and completely positive tensors. In this way, a comprehensive spectral
theory of tensors is developed. I co-organized the International Conference of Spectral Theory of Tensors at Chern Math
Research Institute, Tainjin in 2012, the International Conference on Tensors and Matrices at Suzhou in 2014, the International
Conference on Tensors, Matrices and Their Applications at Chern Math Research Institute, Tainjin in 2016. In 2017, I published
the book “Tensor Analysis: Spectral Theory and Special Tensors’’ by SIAM. This year, I published another book “Tensor Eigenvalues
and Their Applications’’ at Springer.

The Hong Kong Polytechnic University 149

Our Researchers

Department of Applied Mathematics

Dr QIAO Zhonghua

Associate Professor

Phone Number (852) 2766 6932
Email
Education [email protected]

Research Interests Ph.D. Hong Kong Baptist University
ORCiD
Publication M.Sc. Zhengzhou University
H-index
Sum of the Times Cited B.Sc. Zhengzhou University

Numerical Analysis and Scientific Computing

0000-0002-0553-1404

42

13

381

Award Publications (selected)

• 2013-2014 Early Career Award, The Research Grants • Ju L., Li X., Qiao Z. and Zhang H., Energy stability
Council of Hong Kong and error estimates of exponential time differencing
schemes for the epitaxial growth model without slope
Editorial Positions selection, Math. Comp. 87 (2018), 1859-1885.

• Associate Editor of International Journal of Numerical • Li D., Qiao Z. and Tang T., Characterizing the
Analysis and Modeling, 2017-present Stabilization Size for Semi-Implicit Fourier-Spectral
Method to Phase Field Equations, SIAM J. Numer.
• Associate Editor of Advances in Applied Mathematics Anal. 54 (2016),1653-1681.
and Mechanics, 2014-present
• Qiao Z., Tang T. and Xie H., Error Analysis of a Mixed
Research Grants (selected) Finite Element Method for the Molecular Beam Epitaxy
Model, SIAM J. Numer. Anal., 53 (2015), 184-205.
• Principal Investigator, RGC Grant, Stability analysis and
error estimates of exponential time differencing schemes • Qiao Z., Sun Z. and Zhang Z., Stability and convergence
for nonlocal phase field equations, 2018-2020 of second-order schemes for the nonlinear epitaxial
growth model without slope selection, Math. Comp. 84
• Principal Investigator, RGC Grant, L-infinity stability (2015), 653-674.
of semi-implicit schemes for phase field equations,
2017-2019 • Qiao Z. and Sun S., Two-Phase Fluid Simulation Using a
Diffuse Interface Model with Peng–Robinson Equation
• Principal Investigator, RGC Grant, Adaptive numerical of State, SIAM J. Sci. Comput., 36 (2014), B708-B728.
methods for the Boltzmann equation, 2014-2017
• Chen H., Chen S. and Qiao Z., C-0-nonconform-
• Principal Investigator, RGC Grant, Error estimates for ing tetrahedral and cuboid elements for the three-
numerical solutions of epitaxy growth equations, dimensional fourth order elliptic problem, Numerische
2014-2016 Mathematik, 124 (2013), 99-119.

• Principal Investigator, RGC Grant, Numerical solution of • Cai, Z., Li R. and Qiao Z., NRxx Simulation of Microflows
a nonlinear fourth-order parabolic equation for epitaxial with Shakhov Model, SIAM J. Sci. Comput., 34 (2012),
growth, 2012-2014 A339-A369.

• PrincipalInvestigator,RGC G rant, M oving m eshmethods • Qiao Z., Zhang Z. and Tang T., An Adaptive
for reaction-diffusion systems on growing domains, Time-Stepping Strategy for the Molecular Beam Epitaxy
2010-2012 Models, SIAM J. Sci. Comput., 33 (2011), 1395-1414.

150 Research at FAST

Research Overview Department of Applied Mathematics

Dr Qiao concentrates on the design, analysis, and implementation of efficient numerical methods to partial differential
equations. His interest is on the numerical investigation of nonlinear parabolic equations in phase-field simulations, which
have become important and popular in many applications.

Energy Stable Numerical Methods for Molecular Beam Epitaxial Models

Numerical methods have been extensively studied for investigating thin film epitaxial growth. A class of typical
governing equations are of Ehrlich-Schowoebel type, which have complex solution dynamics. Meanwhile, a large time simulation
is required to reach the steady state of numerical solutions. In our research, several highly efficient numerical methods have been
developed for the thin film epitaxial growth simulations, which preserve the energy stability of the system.

Qiao Z, Sun Z. and Zhang Z., Math Comp., 2015.

Energy Stable Numerical Methods for Hydrocarbon Multi-phase Fluid Systems in the Petroleum Industry

Two-phase fluid systems are simulated using a diffusive interface model with the Peng–Robinson equation of state
(EOS), a widely used realistic EOS for hydrocarbon fluid in the petroleum industry. Our algorithm is able to solve
successfully the spatially heterogeneous two- phase systems with the Peng–Robinson EOS in multiple spatial
dimensions, the first time in the literature. Our computational results are compared with laboratory experimental
data and verified with the Young–Laplace equation with good agreement.

Qiao Z. and Sun S., SIAM J. Sci. Comput., 2014.

The Hong Kong Polytechnic University 151

Our Researchers

Department of Applied Mathematics

Prof. SUN Defeng

Chair Professor of Applied Optimization and Operations Research

Phone Number (852) 2766 6935
Email
Education [email protected]

Research Interests Ph.D. Chinese Academy of Sciences

ORCiD M.Sc Nanjing University
Publication
H-index B.Sc. Nanjing University
Sum of the Times Cited
Matrix Optimization, High-Dimensional Statistical Optimization,

Second Order Variational Analysis, Risk Management and

Computational Finance

0000-0003-0481-272X

73

31

2811

Awards and Honours (selected) Publications (selected)

• Plenary speaker at “SIAM Conference on Optimization • Xudong Li, Defeng Sun, and Kim Chuan Toh, “A block
(OP11)”, Darmstadtium Conference Center, Darmstadt, symmetric Gauss-Seidel decomposition theorem for
Germany, May 16-19, 2011 convex composite quadratic programming and its
applications”, Mathematical Programming, (2018)
• Outstanding Scientist Award, by Faculty of Science, 1-24.
National University of Singapore, 2007
• Xin Yee Lam, J.S. Marron, Defeng Sun, and Kim Chuan
Editorial Services Toh, “Fast algorithms for large scale generalized
distance weighted discrimination”, Journal of
• Associate Editor, Mathematical Programming (Series A, Computational and Graphical Statistics, (2018) to
August 2007 - ; Series B, January 2014 - December appear.
2017).
• Chao Ding, Defeng Sun, Jie Sun, and Kim Chuan Toh,
• Associate Editor, SIAM Journal on Optimization (January “Spectral operators of matrices”, Mathematical
2012 -). Programming 168 (2018) 509-531.

• Associate Editor, Journal of the Operations Research • Xudong Li, Defeng Sun, and Kim Chuan Toh, “A highly
Society of China (2012 -). efficient semismooth Newton augmented Lagrangian
method for solving Lasso problems’’, SIAM Journal on
• Associate Editor, Journal of Computational Mathematics Optimization 28 (2018) 433-458.
(2017 -).
• Xinyuan Zhao, Defeng Sun and Kim-Chuan Toh, “A
• Editor-in-chief, Asia-Pacific Journal of Operational Newton-CG augmented Lagrangian method for semi-
Research (October 2010 - December 2013). Advisory definite programming,” SIAM J. on Optimization 20
Committee Member from January 2014. (2010) 1737-1765.

• Associate Editor, Science China Mathematics (January • Defeng Sun, Jie Sun and Liwei Zhang, “The rate of
2018 -). convergence of the augmented Lagrangian method
for nonlinear semidefinite programming,” Mathematical
Programming 114 (2008) 349-391.

• Defeng Sun, “The strong second order sufficient
condition and constraint nondegeneracy in nonlinear
semidefinite programming and their implications,”
Mathematics of Operations Research 31 (2006) 761-776.

• Defeng Sun and Jie Sun, “Semismooth matrix valued
functions,” Mathematics of Operations Research 27
(2002) 150-169.

• Liqun Qi, Defeng Sun and Guanglu Zhou, “A new
look at smoothing Newton methods for nonlinear
complementarity problems and box constrained
variational inequalities,” Mathematical Programming
87 (2000) 1-35.

152 Research at FAST

Research Grants (selected) Department of Applied Mathematics

• Principal Investigator, “Research on Correlation Matrices in Financial Risk Management”. Source: Institute of Risk
Management, National University of Singapore. Duration: 2015 - 2018. Amount: SG$60,000.

• Principal Investigator, “Practical Augmented Lagrangian Methods with Indefinite Proximal Terms”. Source: Academic
Research Fund, National University of Singapore. Duration: December 2014 - December 2017. Amount: SG$141,400.

• Principal Investigator (co-PI from 2015 to July 2016), “Future Resilient System Module 1.1.2 Hidden Interdependencies”.
Source: the Singapore-ETH Centre (SEC) funded by MOE and NRF. Duration: 2015 - 2019. Amount: SG$642,000.

• Co-Principal Investigator, “Large Scale Convex Matrix Optimization: Theory, Algorithms, and Applications”. Source: Academic
Research Fund, Ministry of Education, Republic of Singapore. Duration: April 2014 - March 2017. Amount: SG$592,129

Research Overview

Prof. Sun’s research is mainly in continuous optimization. He has written a number of software for solving large-scale complex
optimization problems, including SDPNAL/SDPNAL+ for general purpose large scale semidefinite programming, codes for
correlation matrix calibrations and most recently the packages including LassoNAL for various statistical regression models. Cur-
rently Prof. Sun focuses on establishing the foundation for the next generation methodologies for big data optimization and
applications.

Exploiting the Second Order Nonsmoothness to Design Efficient Methods for Large Scale Composite
Optimization ProblemsOptimization Problems

In this project, we shall conduct extensive research on the second order nonsmoothness (SON) property exhibited in
big composite optimization models and show how the SON property can be fully exploited to design efficient and robust
algorithms to overcome the numerical difficulties either in interior point methods or in the first order methods. Our research is
motivated by our recent discovery that for the well-known LASSO and support vector machine models the SON property allows
one to design highly efficient and robust semismooth Newton based augmented Lagrangian methods with sub-problems being able
to be solved at costs comparable or even lower than those from many first order methods. For example, one can reduce the
computational cost from O(m^2 n)to O(m^2 p) on using the SON property for the Lasso problem, where m is the sample size,
n is the dimension of the decision vector and p is the number of extracted features. Highly efficient numerical software for large
scale composite optimization models with various nonsmooth penalty terms will also be developed.

Optimization Models and Algorithms for Feature Extractions of Financial Big Data

Today, for organizations and their finance functions, data represents the ultimate challenge and the ultimate opportunity.
With the advent of the internet and social media, humans have access to massive amounts of new data. These new data are
unstructured in the sense that they can come from multiple origins. Hence these data are commonly called ”Big Data”. It is well
known that the ability to collect, manage and analyze big data effectively can lead to better business decisions and lasting
competitive advantages. Given the nature and the specificities of the big data, we must develop a very reliable approach to
analyze the data and extract the relevant information in real time. The goal of this research project is to illustrate how to connect
the big data with the financial models. Our research project intends to be conducted in two ways. One is on how to use the deep
learning techniques to deal with the big data and extract some relevant information from big data. Another one is focused on
designing some more efficient financial models in financial prediction and classification, such as analyzing the factors of stock
or the estimating implied volatilities of options, and proposing some highly efficient algorithms to solve the financial optimization
models.

The Hong Kong Polytechnic University 153

Our Researchers

Department of Applied Mathematics

Dr SZE Nung Sing Raymond

Associate Professor

Phone Number (852) 2766 5642
Email
Education [email protected]

Research Interests Ph.D. The University of Hong Kong
ORCiD
Publication M.Phil. The University of Hong Kong
H-index
Sum of the Times Cited B.Sc. The University of Hong Kong

Matrix Theory, Operator Theory, Quantum Information

0000-0003-1567-2654

58

12

447

Award Publications (selected)

• Journal of Mathematical Analysis and Applications • P.S. Lau, C.K Li, Y.T. Poon, and N.S. Sze, Convexity
(JMAA) Ames Award, 2014 and star-shapedness of matricial range, Journal of
Functional Analysis, in press.
Editorial Position
• C.K. Li, M. Nakahara, Y.T. Poon, and N.S. Sze,
• Member of Editorial Board, Linear and Multilinear Algebra Maximal noiseless code rates for collective rotation
channels on qudits, Quantum Information Processing,
Research Grants (selected) 14:4039-4055, 2015.

• RGC ECS (PI), Quantum Error Correction in Quantum • U. Gungordu, C.K. Li, M. Nakahara, Y.T. Poon, and
Information, 2013-2017 N.S. Sze, Recursive encoding and decoding of
the noiseless subsystem for qudits, Phys. Rev. A,
• RGC GRF (PI), Entanglement in Quantum Information 89:042301, 2014.
Science, 2012-2014
• C.K. Li and N.S. Sze, Determinantal and eigenvalue
• RGC GRF (PI), Mathematical Aspect of Quantum inequalities for matrices with numerical ranges in a
Computing, 2011-2013 sector, J. Math. Anal. Appl., 410:487-491, 2014.

• C.K. Li, M. Nakahara, Y.T. Poon, N.S. Sze, and H. Tomita,
Recovery in quantum error correction for general noise
without measurement, Quantum Information &
Computation, 12:149-158, 2012.

• C.K. Li, M. Nakahara, Y.T. Poon, N.S. Sze, and H.
Tomita, Recursive encoding and decoding of
noiseless subsystem and decoherence free subspace,
Phys. Rev. A 84:044301, 2011.

• C.K. Li, M. Nakahara, Y.T. Poon, N.S. Sze, and H. Tomita,
Efficient quantum error correction for fully correlated
noise, Phys. Lett. A, 375:3255-3258, 2011.

• H.L. Gau, C.K. Li, Y.T. Poon, and N.S. Sze, Higher rank
numerical ranges of normal matrices, SIAM J. Matrix
Analysis Appl, 32:23-43, 2011.

• S.J. Kirkland, M. Neumann, and N.S. Sze, On optimal
condition numbers for Markov chains, Numerische
Mathematik, 110:521-537, 2008.

• C.K. Li and N.S. Sze, Canonical forms, higher rank
numerical range, totally isotropic subspaces, and
matrix equations, Proc. Amer. Math. Soc., 136:
3013-3023, 2008.

154 Research at FAST

Research Overview Department of Applied Mathematics

Dr Sze’s current research interests are in the area of quantum computation and quantum information science, specifically
the related mathematical problems in matrix and operator theory. Research topics involve quantum error correction and
generalized numerical ranges. Other topics of interests include sensitivity analysis in nonnegative matrix theory and preserver
problems.

Higher Rank Numerical Range

The higher rank numerical range (also called rank-k numerical range) is closely connected to the construction of quantum error
correction code for a noisy quantum channel. Mathematically, the higher rank numerical range is a generalization of the classical
numerical range. The numerical range of an operator is the set of quadratic forms on unit vectors determined by the operator.
The theory of quadratic forms appears in many parts of mathematics and science, and has a long and distinguished history.
Researchers are interested in the algebraic and geometric properties of generalized numerical ranges and their applications
to many branches of applied mathematics and other fields of science and engineering.
REF: PAMS2008, JMAA2008, SIMAX2011

The rank-2 numerical ranges of a 5 x 5 normal matrix (top), a 9 x 9 normal matrix (middle), and a 5 x 5 non-normal matrix (bottom).

Quantum Error Correction

The idea of quantum error correction is to protect quantum information from errors due to decoherence and other quantum noise
during the transmission of information in quantum channels. One fundamental question of quantum error correction is the existence
of quantum error correcting code for a noisy quantum system. In this study, some practical and effective implementation
schemes including circuit diagrams are proposed which provide insight into new correcting codes and improve design of
existing codes.
REF: PLA2011, PRA2011, QIC2012, PRA2014, QIP2015

The Hong Kong Polytechnic University 155

Our Researchers

Department of Applied Mathematics

Dr WANG Zhian

Associate Professor

Phone Number (852) 2766 6926
Email
Education [email protected]

Research Interests Postdoc. IMA, University of Minnesota

ORCiD Ph.D. University of Alberta
Publication
H-index M.Sc. Central China Normal University
Sum of the Times Cited
B.Sc. Central China Normal University

Partial Differential Equations and their applications to Biology and Life

Sciences with a focus on Chemotaxis and related topics

0000-0003-2945-5810

44

17

733

Honours and Awards • J. Li. T. Li and Z.A. Wang, Stability of traveling waves
of the Keller-Segel system with logarithmic sensitivity,
• JMAA Ames Award, 2012 Math. Models Methods Appl. Sci., 24(14): 2819-2849,
2014.
• MBI Early Career Award, 2011
• Y.S. Tao and Z.A. Wang, Competing effects of attraction
• IMA Postdoctoral Fellowship, 2007-2009 vs. repulsion in chemotaxis, Math. Models Methods
Appl. Sci., 23: 1-36, 2013.
Research Grants (selected)
• Z.A. Wang, M. Winkler and D. Wrzosek, Global regularity
• RGC GRF (PI), Boundary layers of the singular versus infinite-time singularity formation in
Keller-Segel chemotaxis and application, 2018-2020 a chemotaxis model with volume-filling effect
and degenerate diffusion, SIAM J. Math. Anal., 44:
• RGC GRF (PI), On the stability of traveling waves in 3502-3525, 2012.
chemotaxis models, 2016-2018
• M.J. Ma, C.H. Ou and Z.A. Wang, Stationary solutions
• RGC ECS (PI), Mathematical studies on the attraction- of a volume-filling chemotaxis model with logistic
repulsion Keller-Segel model, 2014-2016 growth and their stability, SIAM J. Appl. Math., 72:
740-766, 2012.
Publications (selected)
• T. Li and Z.A. Wang, Steadily propagating waves of a
• H.Y. Jin, Y.-J. Kim and Z.A. Wang, Boundedness, chemotaxis model, Mathematical Biosciences, 240:
stabilization and pattern formation driven by density- 161-168, 2012.
suppressed motility, SIAM J. Appl. Math., to appear,
2018. • R. Lui and Z.A. Wang, Traveling wave solutions from
microscopic to macroscopic chemotaxis models, J.
• Q.Q. Hou, C.J. Liu, Y.G. Wang and Z.A. Wang, Stability Math. Biol, 61: 739-761, 2010.
of boundary layers for a viscous hyperbolic system
arising from chemotaxis: one dimensional case, SIAM • T. Li and Z.A. Wang, Nonlinear stability of traveling
J. Math. Anal., to appear, 2018. waves to a hyperbolic-parabolic system modeling
chemotaxis, SIAM J. Appl. Math., 70: 1522-1541, 2009.
• V. Martinez, Z.A. Wang and K. Zhao, Asymptotic and
viscous stability of large-amplitude solutions of a
hyperbolic system arising from biology, Indiana Univ.
Math. J., to appear, 2018.

• M. Ma and Z.A. Wang, Global bifurcation and stability
of steady states for reaction-diffusion-chemotaxis
model with volume-filling effect, Nonlinearity,
28:2639-2660, 2015.

• M. Mei, H. Peng and Z.A. Wang, Asymptotic profile of
a parabolic-hyperbolic system with boundary effect
arising from tumor angiogenesis, J. Differential Equations,
259: 5168-5191, 2015.

156 Research at FAST

Research Overview Department of Applied Mathematics

My research interest is mainly on the modeling and analysis of PDE problems arising from biology with a focus on chemotaxis.
So far, my research includes existence and stability of traveling waves of chemotaxis, boundary layers of chemotaxis system,
pattern formation and asymptotic dynamics of cell motility models and global stability of prey-taxis models. The results of these
research topics will uncover the underling mechanisms of abundant pattern formations of chemotaxis such as traveling wave
propagations, boundary layers and aggregates. To achieve these results, in addition to employing various existing methods and
tools, we develop some news ideas such as variable transformations, weighted energy estimates and so on.
• Stability of traveling waves of chemotaxis
• Boundary layers of the singular chemotaxis models

• Pattern Formation of Chemotactic Motion

The Hong Kong Polytechnic University 157

Our Researchers

Department of Applied Mathematics

Dr WONG Kin Yau

Assistant Professor

Phone Number (852) 3400 8983
Email [email protected]
Education Ph.D. The University of North Carolina at Chapel Hill
M.Phil. The University of Hong Kong
Research Interests B.Sc. The University of Hong Kong
High-dimensional Data Analysis, Integrative Analysis of Genomic
ORCiD Data, Latent Variable Modeling, Statistical Genetics, Survival Analysis
Publication 0000-0001-9066-1619
H-index 8
Sum of the Times Cited 3
34

Awards and Honours Publications (selected)

• Barry H. Margolin Dissertation Award, 2018, School of • Wong, K. Y., Zeng, D., and Lin, D. Y. Efficient Es-
Public Health Alumni Association, University of North timation for Semiparametric Structural Equation
Carolina at Chapel Hill Models With Censored Data. Journal of the American
Statistical Association [online], DOI:10.1080/01621
• Distinguished Student Paper Award, 2018, Section on 459.2017.1299626.
Statistics in Genomics and Genetics, American Statistical
Association • Wong, K. Y., Goldberg, Y., and Fine, J. P. (2016).
Oracle Estimation of Parametric Models Under
• Distinguished Student Paper Award, 2016, Eastern North Boundary Constraints. Biometrics, 72:1173–1183.
American Region (ENAR), International Biometric Society
• Lam, K. F. and Wong, K. Y. (2014). Semiparametric
• Special Commendation for Theory Section of Doctoral Analysis of Clustered Interval-Censored Survival
Qualifying Exam, 2013, Department of Biostatistics, Data With a Cure Fraction. Computational Statistics
University of North Carolina at Chapel Hill & Data Analysis, 79:165–174.

• Croucher Scholarship for Doctorate Study, 2012 – 2015, • Lam, K. F., Wong, K. Y., and Zhou, F. (2013). A Semi-
Croucher Foundation parametric Cure Model for Interval-Censored Data.
Biometrical Journal, 55:771–788.
• Sir Edward Youde Memorial Honorary Fellowship for
Overseas Studies, 2012, Sir Edward Youde Memorial • Wong, K. Y. and Lam, K. F. (2013) Modeling
Fund, Hong Kong SAR Government Zero-Inflated Count Data Using a Covariate-Dependent
Random Effect Model. Statistics in Medicine,
32:1283–1293.

158 Research at FAST

Research Overview Department of Applied Mathematics

Recent technological advances have made it possible to collect different types of genomics data, including DNA copy number,
somatic mutation, and expression levels of mRNA, microRNA, and protein, on a large number of subjects. It is of great interest
to integrate multiple genomics data types for understanding disease mechanisms and predicting disease outcomes. Integrative
analysis of genomics data is challenging for various reasons. First, the relationships among different genomic variables are
complex; see the figure below for the potential relationships among variables. Second, each type of genomics data
is high-dimensional. Third, there are substantial missing data in large-scale genomic studies. We are interested in developing
statistical methods that accommodate the complexity of the data.

Prediction of Survival Time Using Multiple Types of High-dimensional Genomics Data

We proposed a variable selection method, termed Integrative Boosting (I-Boost) that combines penalization with statistical
boosting. I-Boost makes proper use of all available genomics data, which are potentially high-dimensional, for the prediction
of patient survival time. Through simulation studies and applications to data sets from The Cancer Genome Atlas (https://
tcga-data.nci.nih.gov/tcga/), we demonstrate that I-Boost provides substantially higher prediction accuracy than existing
variable selection methods.

Variable Selection with Partially Missing Data

A common issue with multi-platform genomics data is that certain data types are missing for a subset of subjects. This
makes statistical analyses, in particular variable selection, using all data types challenging. Currently, ad-hoc meth-
ods, such as discarding subjects with missing data and using single imputation to artificially create a full data set, are
commonly used in practice. However, such methods are not statistically efficient and may lead to biased results. For
variable selection with high-dimensional, partially missing data, we propose a joint latent variable model to characterize
the relationships among the variables and to infer missing values from observed data. Under this formulation, we develop
a computationally efficient algorithm for variable selection that involves only low-dimensional numerical integration.

The Hong Kong Polytechnic University 159

Our Researchers

Department of Applied Mathematics

Dr XU Zuoquan

Associate Professor

Phone Number (852) 2766 6962
Email
Education [email protected]

Research Interests Ph.D. The Chinese University of Hong Kong
ORCiD
Publication M.Phil. Peking University
H-index
Sum of the Times Cited B.Sc. Nankai University

Risk Management, Mathematical Finance, Mathematical Control

0000-0001-6824-1634

15

4

95

Awards (selected) • Zuo Quan Xu, and Jia-An Yan, A Note on the
Monge-Kantorovich Problem in the Plane,
• Department Best Teacher Award 2017/18 Communications on Pure and Applied Analysis,
Vol. 14 (2015), 517-525.
• Department Best Paper Award 2013/14
• Zuo Quan Xu, Investment under Duality Risk Measure,
• Nomura Research Fellow, 2007-2010 European Journal of Operational Research, Vol.
239 (2014), 786-793.
Research Grants (selected)
• Zuo Quan Xu, and Xun Yu Zhou, Optimal Stopping
• Optimal Stopping under Drift Uncertainty, HKGRF, under Probability Distortion, Annals of Applied
2018-2020 Probability, Vol. 23 (2013), 251-282.

• Investment Models with Intractable Claims, HKGRF, • Min Dai, and Zuo Quan Xu, Optimal Redeeming
2017-2019 Strategy of Stock Loans with Finite Maturity, Mathematical
Finance, Vol. 21 (2011), 775-793.
• Consumption-Investment Models with Constraints,
NSFC, 2015-2018 • Min Dai, Zuo Quan Xu, and Xun Yu Zhou, Continuous-
Time Markowitz’s Model with Transaction Costs,
Publications (selected) SIAM Journal on Financial Mathematics, Vol. 1
(2010), 96-125.
• Yongwu Li, and Zuo Quan Xu, Optimal insurance
design with a bonus, Insurance Mathematics and • Albert Shiryaev, Zuoquan Xu, and Xun Yu Zhou,
Economics, Vol. 77 (2017), 111-118. Thou Shalt Buy and Hold, Quantitative Finance,
Vol. 8 (2008), 765-776.
• Xun Li, and Zuo Quan Xu, Continuous–Time
Mean–Variance Portfolio Selection with Constraints • Hanqing Jin, Zuo Quan Xu, and Xun Yu Zhou, A
on Wealth and Portfolio, Operations Research Letters, Convex Stochastic Optimization Problem Arising
Vol. 44 (2016), 729-736. from Portfolio Selection, Mathematical Finance,
Vol. 18 (2008), 171-184.
• Zuo Quan Xu, A Note on the Quantile Formulation,
Mathematical Finance, Vol. 26 (2016), 589-601.

• Zuo Quan Xu, and Fahuai Yi, An Optimal Consumption-
Investment Model with Constraint on Consumption,
Mathematical Control and Related Fields, Vol. 6
(2016), 517-534.

• Danlin Hou, and Zuo Quan Xu, A Robust Markowitz
Mean-Variance Portfolio Selection Model with an
Intractable Claim, SIAM Journal on Financial Mathematics,
Vol. 7 (2016), 124-151.

160 Research at FAST

Research Overview Department of Applied Mathematics

My main research interests are in understanding financial markets and human behaviors by modeling and theoretical analysis of
them. My current research focuses on quantitative analysis of behavioral finance and insurance models, including the development
of quantile method. I have also contributed to the theory and development of stochastic control and PDE with applications in
finance.

Optimal Redeeming Strategy of Stock Loans with Finite Maturity

A stock loan is a loan, secured by a stock, which gives the borrower the right to redeem the stock at any time before or on the
loan maturity. The way of dividends distribution has a significant effect on the pricing of stock loans and the optimal redeeming
strategy adopted by the borrower. We present the pricing models of the finite maturity stock loans subject to various ways of
dividend distribution. Because closed-form price formulas are generally not available, we provide a thorough analysis to
examine the optimal redeeming strategy. Numerical results are presented as well.

Optimal Insurance Design with a Bonus

This paper investigates an insurance design problem, in which a bonus will be given to the insured if no claim has been made
during the whole lifetime of the contract, for an expected utility insured. In this problem, the insured has to consider the
so-called optimal action rather than the contracted compensation (or indemnity) due to the existence of the bonus. For
any pre-agreed bonus, the optimal insurance contract is given explicitly and shown to be either the full coverage contract
when the insured pays high enough premium, or a deductible one otherwise. The optimal contract and bonus are also derived
explicitly if the insured is allowed to choose both of them. The contract turns out to be of either zero reward or zero deductible.
In all cases, the optimal contracts are universal, that is, they do not depend on the specific form of the utility of the insured.
A numerical example is also provided to illustrate the main theoretical results of the paper.

The Hong Kong Polytechnic University 161

Our Researchers

Department of Applied Mathematics

Prof. YANG Xiaoqi

Professor

Phone Number (852) 2766 6954
Email
Education [email protected]

Research Interests Ph.D. University of New South Wales

ORCiD M.Sc. Chinese Academy of Science
Publication
H-index B.Sc. Chongqing Jianzhu University
Sum of the Times Cited
Mathematical Optimization, Vector Optimization, Variational Analysis,

Financial Optimization

0000-0002-5583-4032

230

35

3794

Awards (selected) • Meng K.W. and Yang X.Q. Equivalent conditions for
local error bounds. Set-Valued and Variational Analysis.
• The Faculty Award for Outstanding Performance/ Vol. 20 (2012), no. 4, pp. 617-636.
Achievement 2016/17 - Research and Scholarly Activities
• Fang D.H., Li C. and Yang X.Q. Stable and total
• The First Prize of Natural Science from the Chongqing Fenchel duality for DC optimization problems in
Municipal Government in 2006 locally convex spaces. SIAM J. on Optimiz. Vol. 21
(2011), pp. 730-760.
• Most Active New Consultant, The Hong Kong Polytechnic
University, 2003 • Meng K.W. and Yang X.Q. Optimality Conditions via
Exact Penalty Functions SIAM J. on Optimization.
• The President’s Awards, The Hong Kong Polytechnic Vol. 20 (2010), pp. 3208-3231.
University, for outstanding performance and
achievements in Research and Scholarly Activities • Zheng X.Y. and Yang X.Q. Weak sharp minima for
2000 semi-infinite optimization problems with applications.
SIAM J. on Optimization. Vol. 18 (2007), pp. 573-588.
• ISI Citation Classic Award 2000
• Huang X.X. and Yang X.Q. Generalized Levitin- Polyak
Publications (selected) well-posedness in constrained optimization, SIAM J.
on Optimization. Vol. 17 (2006), no. 1, pp. 243-258.
• Hu, Y.H.; Li, C.; Meng, K.W.; Qin, J. and Yang, X.Q.
Group sparse optimization via l_p,q regularization. • Deng S. and Yang X.Q. Weak sharp minima
J. Mach. Learn. Res. Vol. 18 (2017), Paper No. 30, in multicriteria linear programming, SIAM J. on
pp. 1-52. Optimization. Vol. 15 (2004), pp. 456-460.

• Hu, Y.H.; Li, C.; Yang, X.Q. On convergence rates of • Huang, X. X. and Yang, X. Q. A unified augmented
linearized proximal algorithms for convex composite L a g r a n g i a n a p p r o a c h t o d u a l i t y a n d e x a c t
optimization with applications. SIAM J. Optim. Vol. penalization. Mathematics of Operations Research
26 (2016), no. 2, 1207-1235. Vol. 28 (2003), pp. 533-552.

• Hu Y.H., Yang X.Q. and Sim C.K. Inexact subgradient
methods for quasi-convex optimization problems.
European J. Oper. Res. Vol. 240 (2015), no. 2, pp. 315-327.

• Wang C.Y., Yang X.Q. and Yang X.M. Nonlinear
augmented Lagrangian and duality theory, Math-
ematics of Operations Research. Vol. 38 (2013),
pp.740-760.

• Fang Y.P., Meng K.W. and Yang X.Q., Piecewise linear
multi-criteria programs: the continuous Case and
its discontinuous generalization. Operations Research
Vol. 60 (2012), pp. 398-409.

162 Research at FAST

Research Overview Department of Applied Mathematics

My research focus/expertise includes penalty/augmented Lagrangian theory and methods in nonlinear optimization, error
bound analysis and piecewise linear functions in variational analysis and portfolio selection problems with transaction
cost and sparsity constraint in financial optimization.

Generalized Polyhedral Theory with Applications

The bicriteria portfolio selection with an risk measure and transaction cost is formulated as the following piecewise linear
program:

The graphic representation of a semi-closed polyhedron

The discontinuous piecewise linear term cj(xj) (the transaction cost) prompts us to investigate a generalized polyhedral theory, which
includes a general algebraic representation of a semi-closed polyhedron. More specifically, for the graph P (shadowed
part) on the above, we are able to obtain an algebraic representation by introducing an additional vertex z4, that is

We have also designed some objective space algorithms for finding the (weak) Pareto point set of the continuous bi- criteria
piecewise linear program and the discontinuous one respectively. We are able to plot the efficient frontier up to 12 stocks within
reasonable computing time. The representative publication of this project is: Fang Y.P., Meng K.W. and Yang X.Q., Piecewise
linear multi-criteria programs: the continuous Case and its discontinuous generalization. Operations Research Vol. 60 (2012) pp.
398–409.

Nonlinear Constrained Sparse Optimization with Lower Order Regularization

Nearly, all of the optimization theory and algorithms developed for compressed sensing signal recovery assume that
samples are taken using linear measurements:
To recover the exact solution  we propose the following lower order group regularization problem

We have established the following global recovery bound for the estimated error:

Graphically, see the figure below for the variation of the estimated error and the bound.
We also investigate a projected proximal gradient method to solve the lower order regularization problem, and establish
the convergence theory by virtue of the projection operator and the Kurdyka-Lojasewicz theory. We have also effectively
applied the proximal gradient method to the real data in gene transcriptional regulation. The representative publication of this
project is: Hu Y.H., Li C., Meng K.W., Qin J. and Yang X.Q. Group sparse optimization via regularization. J. Mach. Learn.
Res. Vol. 18 (2017), Paper No. 30, 52 pp.

The illustration of the global recovery board and the
estimated error

The Hong Kong Polytechnic University 163

Our Researchers

Department of Applied Mathematics

Prof. YIU Ka Fai Cedric

Professor

Phone Number (852) 3400 8981
Email [email protected]
Education Postdoc. University of Oxford
University College London
Research Interests Ph.D. University of Oxford
ORCiD M.Sc. University of Dundee
Publication University of London
H-index Optimization and Optimal Control, Signal Processing, Risk Management
Sum of the Times Cited 0000-0002-7523-4069
107
19
1049

Awards (selected) • Z.G. Feng, K.F.C. Yiu* and S. Nordholm. Performance
limit of broadband beamformer designs in space and
• Third prize in Chongqing Natural Science Foundation frequency, Journal of Optimization Theory and
Award 2014 Applications, 2015.

• AMA PolyU Best Paper Award in 2009, 2012 and 2015 • K.F.C. Yiu*, Z.B. Li, S.Y. Low and S. Nordholm. FPGA
multi-filter system for speech enhancement via multi-
• Best Paper Award, CSO2012 2012 criteria optimization, Applied Soft Computing, 2014.

• Donald Julius Groen Prize 2002 • Z.B. Li, K.F.C. Yiu*, S. Nordholm. On the indoor beam
former design with reverberation, IEEE Transactions on
Patents Audio Speech and Language Processing, 2014.

• Beamforming using a microphone array, US9049503 • J.Z. Liu, K.F.C. Yiu and T.K. Siu. Optimal Investment of
2015 an Insurer with Regime-Switching and Risk Constraint,
Scandinavian Actuarial Journal, 2014.
• Echo Canceller, US6947549 2005
• J.Z. Liu, K.F.C. Yiu, T.K. Siu and W.C. Ching. Optimal
Publications (selected) investment-reinsurance with dynamic risk constraint
and regime switching, Scandinavian Actuarial Journal,
• Z.B. Li, K.F.C. Yiu and Y.H. Dai. On sparse beamformer 2013.
design with reverberation. Applied Mathematical Mod-
elling, 2018. • K.Y. Chan, K.F.C. Yiu, T.S. Dillon and S.H. Ling.
Enhancement of speech recognitions for control auto-
• J.Z. Liu, K.F.C. Yiu and A. Bensoussan. Optimal inven- mation using an intelligent particle swarm optimization,
tory control with jump diffusion and nonlinear dynamics IEEE Transactions on Industrial Informatics, 2012.
in the demand, SIAM Journal on Control and Optimiza-
tion, 2018. • Z.G. Feng, K.F.C. Yiu*, and S.E. Nordholm. Placement
design of microphone arrays in near-field broadband
• Y.H. Ni, K.F.C. Yiu, H.S. Zhang and J.F. Zhang. De- beamformers. IEEE Transactions on Signal processing,
layed optimal control of stochastic LQ problem. SIAM 2012.
Journal on Control and Optimization, 2017.
• K.F.C. Yiu*, Y. Lu, J.Q. Huo, S. Nordholm, C.H. Ho and
• W. Xu, Z.G. Feng, J.W. Peng and K.F.C. Yiu. Optimal W. Luk. Reconfigurable FPGA-based robust frequency-
switching for linear quadratic problem of switched domain echo canceller with applications to voice
systems in discrete time, Automatica, 2017. control device, Digital Signal Processing, 2012.

• J.Z. Liu, K.F.C. Yiu and A. Bensoussan. Optimality of • J.Z. Liu, L.H. Bai and K.F.C. Yiu. Optimal investment
(s, S) policies with nonlinear processes, Discrete and with a value-at-risk constraint, Journal of Industrial and
Continuous Dynamical Systems - Series B, 2017. Management Optimization, 2012.

• M.J. Gao, K.F.C. Yiu*, S. Nordholm, Y.Y. Ye. On a • Z.G. Feng, K.F.C. Yiu* and S. Nordholm. A two-stage method
new SDP-SOCP method for acoustic source localiza- for the design of near-field broadband beamformers,
tion problem, ACM Transactions on Sensor Networks, IEEE Transactions on Signal Processing, 2011.
2016.
• K.F.C. Yiu, J.Z. Liu, T.K. Siu and W.C. Ching. Optimal
Portfolios with Regime-Switching and Value-at-Risk
Constraint, Automatica, 2010.

164 Research at FAST

Research Overview Department of Applied Mathematics
Advanced Signal Processing Techniques via Optimization

Optimization model and global optimization techniques have found many applications in engineering such as in the design of
voice communication devices. Speech is a natural and easy way to have effective communications and to control multimedia
devices. For over two decades, speech control mechanisms have been widely applied. To implement speech controls,
a commercial speech recognizer is used as the interface between users and the automation system. However, we are
surrounded by all kinds of acoustic noise from different sources varying in time and space, and users’ commands are often
contaminated by environmental noise which degrades the performance of speech recognition for controlling automation
systems. In our research, multichannel signal enhancement methodologies are developed to design beamformers so as to
improve the signal quality as well as the performance of commercial speech recognizers.

Optimal Beamformer Designs and Configurations

Advanced Designs with Reverberation and Barriers

Financial Risk Management and Optimal Inventory Management

In many practical management problems, optimal control theory plays a central role in deriving optimal allocations and
policies. Typical uncertainties include asset returns or inventory demands. For example, in finance, one needs to determine
optimal allocation of risky assets with risk constraints. In inventory control, one would want to find optimal inventory policy under
realistic demand stochastic. Toward these directions, we have employed optimal control to tackle several problems and
developed optimal allocations and optimal policies.

The Hong Kong Polytechnic University 165

Our Researchers

Department of Applied Mathematics

Dr YU Xiang

Assistant Professor

Phone Number (852) 2766 6930
Email
Education [email protected]

Research Interests Postdoc. The University of Michigan

ORCiD Ph.D. The University of Texas at Austin
Publication
H-index B.S. Huazhong University of Science and Technology
Sum of the Times Cited
Financial Mathematics, Applied Probability, Stochastic Control and

Optimization

0000-0003-4053-7876

2

1

2

Awards • The Second Paris-Asia Conference in Quantitative
Finance, Suzhou, China, May 2017
• SIAM Early Career Travel Award, USA, 2014
• The 5th Asian Quantitative Finance Conference,
• Graduate School Professional Development Award, UT Seoul, Korea, April 2017
Austin, May 2012
• The 2nd NUS-USPC Workshop on New Challenges in
• SIAM Student Travel Award, USA, 2012 Financial Risk Control, Singapore, April 2017

Research Grants • Department Seminar in System Engineering and
Engineering Management, The Chinese University of
• PROCORE-France/Hong Kong Joint Research Hong Kong, February 2017
Scheme. “Optimal relative consumption with
reference to past spending maximum and the large • Mini-symposium speaker at SIAM Conference on
time asymptotics”, 1/2018-12/2019. Financial Mathematics and Engineering, Austin,
Texas, USA, November 2016
• Hong Kong Early Career Scheme (ECS) Grant.
‘’Duality approach with auxiliary processes in • Probability Seminar, Osaka University, Japan,
some path-dependent portfolio choice problems”, November 2016
1/2017-12/2019.
• Workshop on Dirichlet Forms and Stochastic Analysis,
Invited Talks (selected) Kansai University, Japan, November 2016

• The 10th World Congress of the Bachelier Finance • Workshop on Applied Mathematics, Shandong
Society, Dublin, Ireland, July 16-20, 2018 University, China, June 2016

• The 12th AIMS Conference on Dynamical Systems, Publications
Differential Equations and Applications, Taipei, Taiwan,
July 5-9, 2018 • Jose Luis Perez, Kazutoshi Yamazaki and Xiang Yu.
On the bail-out optimal dividend problem. Journal
• Two days Workshop on Stochastic Control and of Optimization Theory and Applications (2018), to
Applications, VPSMS, Verona, Italy, May 10-11, 2018 appear.

• Workshop on Stochastic Control and Related Issues, • Erhan Bayraktar, Xiang Yu, On the market viability
Osaka, Japan, March 2018 under proportional transaction costs. Mathematical
Finance. Online first, DOI:10.1111/mafi.12155.
• Paris Bachelier Seminar, Institut Henri Poincaré, Paris,
France, January 2018 • Xiang Yu, Optimal consumption under habit forma-
tion in markets with transaction costs and ran-
• Workshop on Stochastic Processes in Actuarial dom endowments. The Annals of Applied Probabil-
Science and Finance, Vietnam Institute for Advanced ity. Vol. 27 (2017), No. 2, pp. 960-1002.
Study in Mathematics, Vietnam, July 2017
• Xiang Yu, Utility maximization with addictive
• Conference on Asymptotic Statistics of Stochastic consumption habit formation in incomplete
Processes and Applications in Finance, Steklov semimartingale markets. The Annals of Applied
Institute, Saint Petersburg, Russia, July 2017 Probability. Vol. 25 (2015), No. 3, pp. 1383-1419.

166 Research at FAST

Research Overview Department of Applied Mathematics

My research interests include broad applied probability models and stochastic control and optimization methods in applications
of quantitative finance. In particular, I am interested in solving various path-dependent optimal investment problems, usually
motivated by finance and economics, using the modified duality approach with auxiliary processes. Meanwhile, I aim to
incorporate this idea of path-dependence into the optimal contracting theory and develop some systematic approaches to obtain
the optimal contract design. I am also currently working on other topics such as optimal investment with credit risk, optimal
investment and pricing under model uncertainty and some projects on information acquisition and human-machine decisions.

Optimal Contracting with Agent’s Consumption Habit Formation

The optimal contracting has grown to be one of the core research topics in quantitative finance and economics, which is to
model the profit-oriented interactions between the owners and employees and resulting contracts design. The so-called
Principal-Agent problem, which resides in this framework, considers two parties and deals with issues when Principal hires
Agent to make decisions and pursue her interest by paying Agent certain incentives. We focus on Moral Hazard circumstances with
asymmetric information such that Principal has no access to observe Agent’s efforts. It is assumed that Agent not only consumes
from his private account, but also develops certain habits with some smooth consumption features through his utility, called the
habit formation preference, which intricately influences his current spending plans. We aim to answer how will Principal offer her
efficient incentives provision according to Agent’s past consumption pattern.

Risk Sensitive Portfolio Optimization with Default Risk and Regime Switching

We study an open problem of risk-sensitive portfolio allocation in a regime-switching credit market with default contagion. The
state space of the Markovian regime-switching process is assumed to be a countably infinite set. To characterize the value
function of the risk sensitive stochastic control problem, we investigate the corresponding recursive infinite-dimensional nonlinear
dynamical programming equations based on default states. We prove the existence and uniqueness of the classical solution to
the system of equations and also provide the feedback form of the optimal trading strategy for this investment problem.

Utility Maximization with Proportional Transaction Costs under Model Uncertainty

This project considers a discrete time financial market with proportional transaction costs under model uncertainty and we study
a semi-static utility maximization for the case of exponential utility preference. Using some randomization techniques, we can
transform the original problem into a frictionless market framework, however, with the extra probability uncertainty on an
enlarged space. This allows us to prove all together the existence of the optimal strategy, the auxiliary dynamic programming
principle as well as the convex duality theorem in our context with transaction costs. As an application of the duality representation,
some important features of utility indifference prices are investigated in this robust setting.

The Hong Kong Polytechnic University 167

Our Researchers

Department of Applied Mathematics

Dr ZHANG Guofeng

Associate Professor

Phone Number (852) 2766 6936
Email
Education [email protected]

Research Interests Ph.D. University of Alberta

ORCiD M.Sc. Northeastern University
Publication
H-index B.Sc. Northeastern University
Sum of the Times Cited
Quantum Information and Control, Sampled-data Control, Nonlinear

Dynamics

0000-0002-8832-1364

48

9

312

Editorial Position • Pan Y., Dong D., and Zhang G., Exact analysis of
the response of quantum systems to two photons
• Guest Associate Editor, The International Journal of using a QSDE approach, New Journal of Physics,
Bifurcation and Chaos 18, 033004, 2016.

Invited Talk • Hu S., Qi L., and Zhang G., Computing the geometric
measure of entanglement of multipartite pure states
• 大會報告,2015年中國智能物聯系統會議,2015年 by means of non-negative tensors, Physical Review
12月,廣州 A, 93, 012304, 2016.

Research Grants • Song H., Zhang G., and Xi Z., Continuous-mode
multi-photon filtering, SIAM Journal on Control and
• Principal Investigator for two GRF grants, 2015-2018, Optimization, 54, 1602-1632, 2016.
2013-2016
• Gough J.E. and Zhang G., On realization theory of
• Principal Investigator for a grant from the National quantum linear systems, Automatica, 59: 139-151,
Natural Science Foundation of China (NSFC), 2015.
2014-2017
• Zhang G., Analysis of quantum linear systems’
• Principal Investigator (China Side) for a Royal Academy response to multi-photon states, Automatica, 50(2):
of Engineering UK-China Exchange grant, 2013-2015 442-451, 2014.

Publications (selected) • Zhang G. and James M. R., On the response of
quantum linear systems to single photon input
• Jing G., Zhang G., Lee H. W. J., and Wang L., Weak fields, IEEE Transactions on Automatic Control,
rigidity theory and its application to formation stabi- 58(5): 1221-1235, 2013.
lization, SIAM Journal on Control and Optimization,
accepted, 2018. • Zhang G., Lee H. W.J., Huang B., and Zhang H.,
Coherent feedback control of linear quantum
• Zhang G., Grivopoulos S., Petersen I. R., and optical systems via squeezing and phase shift,
Gough J. E., The Kalman decomposition for linear SIAM Journal Control and Optimization, 50(4):
quantum systems, IEEE Transactions on Automatic 2130-2150, 2012.
Control, 63, 331-346, 2018.
• Bian C., Zhang G., and Lee H.W.J., Squeezing en-
• Gough J. E. and Zhang G., Classical and quantum hancement of degenerate parametric amplifiers via
stochastic models of resistive and memristive coherent feedback control, International Journal of
circuits, Journal of Mathematical Physics, 58, Control, 85(12):1865-1875, 2012.
073505, 2017.
• Zhang G. and James M.R., Direct and indirect cou-
• Zhang G., Dynamical analysis of quantum linear plings in coherent feedback control of linear quan-
systems driven by multi-channel multi-photon tum systems, IEEE Transactions on Automatic Con-
states,’ Automatica, 83, 186-198, 2017. trol, 56(7): 1535-1550, 2011.

168 Research at FAST

Research Overview Department of Applied Mathematics

My research mainly focuses on quantum information and control; specifically, I am interested in

• understanding how atoms interact with photons with given frequency pulse shapes

• building feedback networks to manipulate atom-photon interaction

• designing quantum filters to read useful information from a quantum system

• computing the degree of entanglement of multi-partite quantum systems

• exploring the structure of quantum linear dynamics

• developing efficient optimization algorithms for quantum computing devices

The Structure of Quantum Linear Systems

A quantum linear system (e.g., an optical cavity) can be mathematically modeled in terms of quantum stochastic differential
equations (QSDEs). Given a set of QSDEs for a quantum linear system, the realization theory studies how to implement it by
means of quantum devices such as optical cavities, beam splitters and phase shifters. We proposed two specific structures for
quantum linear systems. Moreover, we proposed Kalman canonical form for quantum linear systems.

Bus realization and chain realization (from the 8th selected paper) Kalman canonical form of a quantum linear system (from the 2nd selected
paper)
Multi-photon State Processing

A light field is said to be in an n-photon state if it contains exactly n photons. N-photon states are very useful resources in quantum
information sciences such as quantum computing, quantum communication, and quantum metrology. We studied how a quantum
system (e.g., a two-level atom) responds to an n-photon state; in particular, we derived analytic expressions of output pulse
shapes and quantum n-photon filters.

The transmission probability of a two-level emitter driven by a 2-photon state The excitation probability of a two-level emitter driven by a 2-photon state
(from the 6th selected paper) (from the 7th selected paper)

The Hong Kong Polytechnic University 169

Our Researchers

Department of Applied Mathematics

Dr ZHANG Zaikun

Assistant Professor

Phone Number (852) 2766 4592
Email
Education [email protected]

Research Interests Ph.D. Chinese Academy of Sciences

ORCiD B.Sc. Jilin University
Publication
H-index Theory and Algorithms of Mathematical Optimization, especially
Sum of the Times Cited
Randomized Algorithms, Derivative-free Algorithms, Noisy Problems,

and Large-scale Problems

0000-0001-8934-8190

3

2

6

Honours and Achievements Publications

• Member of the Organizing Committee of The 11th • X. Chen, C. T. Kelley, F. Xu, Z. Zhang, A smoothing
International Conference on Numerical Optimization direct search method for Monte Carlo based nonsmooth
and Numerical Linear Algebra (Aug. 8–11, 2017, optimization, to appear in SIAM J. Sci. Comput.
Yinchuan, China)
• S. Gratton, C. W. Royer, L. N. Vicente, Z. Zhang,
• Member of the Organizing Committee of The Fourth Complexity and global rates of trust-region methods
International Conference on ContinuousOptimization based on probabilistic models, to appear in IMA J.
(July 27–Aug. 1, 2013, Lisbon,Portugal) Numer. Anal.

• Maintainer (with N. I. M. Gould) of Professor M. J. D. • M. Dodangeh, L. N. Vicente, Z. Zhang, On the optimal
Powell’s legacy optimization software: TOLMIN, order of worst case complexity of direct search, Optim.
COBYLA, UOBYQA, NEWUOA, BOBYQA, and LINCOA Lett., 10(4): 699–708, 2016.

Research Grants • S. Gratton, C. W. Royer, L. N. Vicente, Z. Zhang, Di-
rect search based on probabilistic descent, SIAM
• Jan 2018 - Dec 2020, “Nonlinear Optimizatio Based J. Optim., 25(3): 1515–1541, 2015.
on Inaccurate Information”, PI, awarded by the
Research Grants Council of Hong Kong under the • Z. Zhang, Sobolev seminorm of quadratic functions
Early Career Scheme with applications to derivative-free optimization, Math.
Program., 146(1–2): 77–96, 2014.
• Jan 2017 - Dec 2018, “Space Decomposition Methods
for Constrained Optimization with Engineering Works in Progress
Applications”, Hong Kong PI (French PI:S. Gratton),
jointly awarded by the Research Grants Council of • S. Gratton, L. N. Vicente, Z. Zhang, A subspace
Hong Kong and le Consulat Général de France à Hong decomposition framework for nonlinear optimization
Kong & Macao under the PROCORE- France/
Hong Kong Joint Research Scheme • F. Delbos, S. Gratton, B. Pauwels, Z. Zhang, Direct
search for noisy functions

• Z. Zhang, A derivative-free optimization algorithm with
low-dimensional subspace techniques for large-scale
problems

170 Research at FAST

Research Overview

Space Decomposition Methods for Constrained Optimization with Engineering Applications

(Funded by RGC under the PROCORE - France/Hong Kong Joint Research Scheme)

This project is a collaboration among Zhang, Gratton, and Gazaix with her Multidisciplinary Design Optimization (MDO)
research team. We plan to study space decomposition methods for constrained optimization, and also investigate the
application of these methods to MDO problems, which are a class of engineering optimization problems with very special
structures that fit the space decomposition methodology. We will extend the highly successful techniques in Domain
Decomposition methods (especially Restricted Additive Schwarz and coarse grid) to nonlinear constrained optimization, in
order to develop scalable parallel optimization algorithms that are well adapted to modern computing environments.

5
NEWUOA
Subspace-0.0
Subspace-0.1

4 Subspace-0.2

3 Department of Applied Mathematics

log(f)

2

1

0 0 500 1000 1500 2000 2500 3000

Number of Function Evaluations

Effectiveness of space decomposition

Nonlinear Optimization Based on Inaccurate Information

(Funded by RGC under the Early Career Scheme)

How does inaccuracy in function values and gradients influence the asymptotic convergence and non-asymptotic complexity
of optimization algorithms that are developed without considering the inaccuracy? How should optimization algorithms
exploit inaccurate function values and gradients to solve problems to desirable precision at low cost? This project will
investigate these two questions. Our project is motivated by applications including meteorological forecasting, reservoir
oil well placement, and environmental engineering, where function values and gradients are often inaccurate. In contrast
to existing works, we will not require the inaccuracy to fade away as iterations proceed. Both deterministic and stochastic
inaccuracies will be studied.

Objective function v.s. Cracle function

The Hong Kong Polytechnic University 171

Our Researchers

Department of Applied Mathematics

Dr ZHAO Xingqiu

Associate Professor

Phone Number (852) 2766 6921
Email
Education [email protected]

Research Interests Ph.D. McMaster University

ORCiD M.Sc. McMaster University
Publication
H-index B.S. Hubei University
Sum of the Times Cited
Survival Analysis, Longitudinal Data Analysis, High-dimensional Data

Analysis

0000-0002-4938-7352

46

11

359

Awards (selected) • Cao, Y., Huang, J., Liu, Y. and Zhao, X., Sieve estimation
of Cox models with latent structures, Biometrics, 72
• 教育部高等學校科學研究優秀成果獎自然科學二等獎 (2016), 1086-1097.
2014
• Zhao, X., Deng, S., Liu, L and Liu, L., Sieve estimation
• 深圳虛擬大學園 2013 年度獲得國家級科技項目先進 in semiparametric modeling of longitudinal data with
個 人,深圳市科技創新委員會 informative observation times, Biostatistics, 15 (2014),
140-153.
Research Grants (selected)
• Gao, F. and Zhao, X., Delta method in large deviations
• Principal Investigator, NSFC, Nonparametric and Semi- and moderate deviations for estimators, The Annals of
parametric Statistical Inference for Panel Count Data, Statistics, 39 (2011), 1211-1240.
2018-2021
• Zhao, X. and Sun, J., Nonparametric comparison for
• Principal Investigator, NSFC, Efficient Estimation Methods panel count data with unequal observation processes,
of Semiparametric Regression Models with Interval- Biometrics, 67 (2011), 770-779.
Censored Data, 2014-2017
• Zhao, X., Zhou, J. and Sun L., Semiparametric trans-
• Principal Investigator, RGC Grant, Structured Selection formation models with time-varying coefficients for
and Estimation in High-Dimensional Survival Models, recurrent and terminal events, Biometrics, 67 (2011),
2013-2016 401-414.

• Principal Investigator, RGC Grant, Analysis of High- • Balakrishnan, N. and Zhao, X., New multi-sample
Dimensional Survival Model, 2012-2014 nonparametric tests for panel count data, The Annals
of Statistics, 37 (2009), 1112-1149.
• Principal Investigator, RGC Grant, Nonparametric
Methods for Panel Count Data with Unequal Observation, • Sun, J., Park, D-H, Sun, L. and Zhao, X., Semiparamet-
2009-2012 ric regression analysis of longitudinal data with informa-
tive observation times. Journal of the American Statisti-
Publications (selected) cal Association, 100 (2005), 882-889.

• Deng, S. and Zhao, X. Covariate-adjusted regression • Sun, J., Zhao, Q. and Zhao, X., Generalized log-rank
for distorted longitudinal data with informative observation test for interval-censored failure time. Scandinavian
times. Journal of the American Statistical Association, Journal of Statistics, 32 (2005), 49-57.
online, DOI: 10.1080/01621459.2018.1482757.

• Gao, F., Xiong, J and Zhao, X., Moderate deviations
and nonparametric inference for monotone functions.
The Annals of Statistics, 46 (2018), 1225-1254.

• Zhao, X., Wu, Y. and Yin, G., Sieve maximum likelihood
estimation for a general class of accelerated hazards
models with bundled parameters, Bernoulli, 23 (2017),
3385-3411.

172 Research at FAST

Research Overview Department of Applied Mathematics
Subgroup Structure and Heterogeneous Effects Estimation in Survival Models

With the development of precision medicine, correct identification of subgroups of a heterogeneous population is very important.
Subgroup analysis presents new and challenging theoretical and computational problems in statistics. Standard methods
assuming the coefficients for treatment variables are subject-independent are not applicable to statistical inference for survival
models with treatment heterogeneity. There appears to be no systematic study on simultaneous variable selection, grouping
structure identification, and subgroup-specific treatment effects estimation procedures for heterogeneous survival models in
high-dimensional settings due to the challenges with censoring and unknown grouping information. The research is expected to
stimulate new research directions for studying subgroup analysis for several classes of important survival analysis models and
panel count data models, including the Cox proportional hazards models, accelerated failure time models, and proportional
means models for panel count data, when there is an unknown grouping structure in subjects. The methods are expected to be
able to correctly identify the grouping structures with high probability, and also select important covariates, identify grouping
structures and estimate subgroup-specific treatment effects simultaneously with high probability in sparse high-dimensional
settings. The research will yield new methods for the analysis of clinical and genomic data with censored survival outcome and
treatment heterogeneity.

Semiparametric and Nonparametric Methods for Longitudinal Data

Longitudinal data include observations on subjects over multiple time points where the response variable is observed only at
observation time points subject to censoring. Such data arise naturally when repeated measures are taken over a period of time. The
choice of method for analyzing longitudinal data usually depends on the relationship among the response variable, the observation
times and the censoring time as well as questions of interest. Most existing methods have been developed under the assumption
that observation times are fixed or random but independent of longitudinal outcomes completely or given covariates. Note that when
the independent censoring assumption, the non-informative observation process assumption, or the specified Poisson-type
observation process assumption is violated, the inference procedures relying on such assumptions would lead to biased conclusions.
Hence, it is necessary to develop new joint modeling approaches for the general situations. On the other hand, the problem of
variable selection and structure identification has not been studied for the analysis of longitudinal data in the presence of
informative observation and terminal event times, and hence, novel methods are needed to address such new challenges.

The Hong Kong Polytechnic University 173

Our Researchers

Department of Applied Mathematics

Dr ZHOU Zhi

Assistant Professor

Phone Number (852) 2766 7865
Email
Education [email protected]

Research Interests Ph.D. Texas A&M University
ORCiD
Publication B.Sc. Nanjing University of Aeronautics and Astronautics
H-index
Sum of the Times Cited Numerical Modeling, Simulation and Analysis

0000-0002-3439-0313

17

7

232

Award • B. Jin, R. Lazarov, J. Pasciak and Z. Zhou, Error analysis
of finite element methods for space-fractional parabolic
• 2017/18 Department Best Paper Award equations, SIAM J. Numer. Anal., 52 (5) (2014),
2272-2294.
Publications (selected)
• B. Jin, R. Lazarov and Z. Zhou, An analysis of the L1
• B. Jin, B. Li and Z. Zhou, An analysis of the crank-nicol- scheme for the subdiffusion equation with nonsmooth
son method for subdiffusion, IMA J. Numer. Anal., 38(1) data, IMA J. Numer. Anal., 36(1) (2014), 197-221.
(2018), 518-541.
• B. Jin, R. Lazarov and Z. Zhou, Error estimates for
• Q. Du, J. Yang and Z. Zhou, Analysis of a nonlocal-in-time a semidiscrete finite element method for fractional or-
parabolic equation, Discrete Contin. Dyn. Syst. Ser. B, der parabolic equations, SIAM J. Numer. Anal., 51 (1)
22 (2) (2017) 339-368. (2013), 445-466.

• B. Jin, R. Lazarov, V. Thomee and Z. Zhou, On
nonnegative preservation in finite element methods for
subdiffusion equations, Math. Comp., 86 (307) (2017)
2239-2270.

• B. Jin, R. Lazarov and Z. Zhou, On two schemes for
fractional diffusion and diffusion wave equations, SIAM
J. Sci. Comput., 38 (1) (2016) A146-A170.

• B. Jin, R. Lazarov and Z. Zhou, A Petrov-Galerkin
finite element method for fractional convection-
diffusion equations, SIAM J. Numer. Anal., 54(1) (2016),
481-503E.

• Bazhlekova, B. Jin, R. Lazarov, and Z. Zhou, An
analysis of the Rayleigh-Stokes problem for a
generalized second-grade fluid, Numer. Math., 131 (1)
(2015), 1-31.

174 Research at FAST

Research Overview

Anomalous Nonlocal Diffusion: Modeling and Analysis

Anomalous diffusion has attracted people’s attention due to its wide applications, e.g., contaminant transport in groundwater,
protein diffusion within cells, thermal diffusion in media with fractal geometry, to name but a few. Meanwhile, the origins and
mathematical models or anomalous diffusion differ significantly. On one hand, the need for experimental standards has been
called for. On the other hand, there is a need for in-depth studies of mathematical models, many of which are non-standard and
nonlocal. The aim of this project is to develop mathematical tools in order to capture the dynamics of anomalous diffusion.
The research will consist of three parts:

• Study the stochastic process behind the nonlocal anomalous diffusion model

• Develop an simple nonlocal model to capture the dynamics of anomalous diffusion

• Analytically study the properties of the nonlocal diffusion models

Department of Applied Mathematics

Experiment results Simulation results

High-order Numerical Schemes for Time-Fractional Diffusion

In this project, we shall study numerical treatment for the time-fractional diffusion equations and derive optimal error bounds that
are expressed with respect to regularity of (possibly very weak) problem data. The research will consist of three parts.

• We will investigate the time-fractional diffusion model involving a time-dependent diffusion coefficient, where existing
techniques, mostly based on Laplace transform, are not directly applicable here. We shall provide sharp regularity as
well as the numerical analysis by a novel perturbation argument. High-order numerical methods will be discussed, using
the convolution quadrature and the initial correction technique.

• We intend to study the stochastic time-fractional diffusion model, where the additional restriction on the smoothing
property is caused by the random noise. The numerical analysis relies crucially on suitable error estimates for the
corresponding deterministic problem with non-smooth data, and a careful study on the inhomogeneous part due to the
stochastic process.

• We shall discuss how to improve the approximation in space, where the solution of time-fractional diffusion model is
non-smooth in space due to the low regularity of the initial data and the presence of the time-fractional derivative.

The Hong Kong Polytechnic University 175

Our Researchers

Department of Applied Physics

Dr CHAI Yang

Associate Professor

Phone Number (852) 2766 5678
Email
Education [email protected]

Research Interests Ph.D. The Hong Kong University of Science and Technology

ORCiD M.Sc. Peking University
Publication
H-index B.Sc. Nanjing University
Sum of the Times Cited
Low-dimensional Materials and Electronics, Flexible Electronics,

Energy Harvesting and Storage

0000-0002-8943-0861

93

22

1327

Awards and Honours photocorrosion resistance and photocatalytics
properties”, Journal of the American Chemistry
•• Semiconductor Science and Technology Early Career Society, 2017, 139(11), 4144-4151.
Award, 2017
••Y.D. Zhao, J.S. Qiao, P. Yu, Z.X. Hu, Z.Y. Lin, S. P.
•• IEEE Distinguished Lecture in Electron Device Society,
2016 Lau, Z. Liu, W. Ji, and Y. Chai*, “Extraordinarily
Strong Interlayer Interaction 2in8(21D2),La2y3e9r9e-d24P0t7S.2”,
•• Early Career Award, Research Grant Council (RGC) Advanced Materials, (2016),
of Hong Kong, 2014-2015
••Yuda Zhao, Jingsi Qiao, Zhihao Yu, Peng Yu, Kang
Patent (selected) Xu, Shu Ping Lau, Wu Zhou, Zheng Liu, Xinran
Wang, Wei Ji*, and Yang Chai*, “High-Electron-
•• “Methods of establishing low-resistance electricalcontact Mobility and Air-Stable 2D Layered PtSe2 FETs”,
to carbon nanostructures with graphiticinterfacial Advanced Materials, 2017, 29, 1604230.
layer” (US20130059134 A1). Inventors: Y. Chai, A.
Hazeghi, K. Takei, A. Javey, and H.-S. Philip Wong Five Publications beyond five years:

Book Chapter •• Y. Chai, A. Hazeghi, K. Takei, H. Y. Chen, Philip C. H.
Chan, A. Javey, and H.-S. Philip Wong, “Graphitic
•• Y. D. Zhao and Y. Chai, “Graphene Nanosheet as interfacial layer to carbon nanotube for low
Ultrathin Barrier,” pp. 343-356, CRC press, (2014). electrical contact resistance”, IEEE International
Book name: Micro- and Nanoelectronics, Emerging Electron Device Meeting (IEDM) Technical Digest,
Device Challenges and Solution. San Francisco, California, USA, Dec., (2010),
pp. 210-213.
Publications (selected)
•• Y. Chai, Y. Wu, K. Takei, H. Y. Chen, S. M. Yu,
Five Publications in recent five years: Philip C. H. Chan, A. Javey, and H.-S. Philip Wong,
••L. F. Fei, S. Lei, W. B. Zhang, W. Lu, Z. Y. Lin, C. “Resistive switching of carbon-based RRAM with
H. Lam, Y. Chai*, Y. Wang*, “Direct TEM Observa- CNT electrodes for ultra-dense memory”, IEEE
tions on Growth Mechanisms of Two- Dimensional International Electron Device Meeting (IEDM) Tech-
MoS2 Flakes”, Nature Communications, (2016), 7, nical Digest, San Francisco, California, USA, Dec.,
12206-1-17. (2010), pp. 214-217.
••Yunpeng Zuo, Dewei Rao, Shuo Li, Tingting Li, Guilin
Zhu, Shuangming Chen, Li Song, Yang Chai,* •• Y. Chai*, Z. Y. Xiao, and Philip C. H. Chan,
and Heyou Han*, “Atomic Vacancies Control of “Low- resistance of carbon nanotube contact plug
Pd-Based Catalysts for Enhanced Electrochemical to silicon”, IEEE Electron Device Letters, Vol. 30,
Performance”, Advanced Materials, 2017, 29, 1704171. No. 8, (2009), pp. 811-813.
••Mengye Wang, Leijuan Cai, Yi Wang, Feichi
Zhou, Kang Xu, Xiaoming Tao, and Yang Chai*, •• Y. Chai* and Philip C. H. Chan, “High electromigration-
“Graphene-draped semiconductors for enhanced resistant copper/CNT composite for interconnect
applications”, IEEE International Electron Device
176 Research at FAST Meeting (IEDM) Technical Digest, San Francisco,
California, USA, Dec., (2008), pp. 607-610.

•• Y. Chai*, Philip C. H. Chan, Y. Y. Fu, Y. C. Chuang,
and C. Y. Liu, “Electromigration studies of Cu/CNT
composite using Blech structure”, IEEE Electron
Device Letters, Vol. 29, No. 9, (2008), pp. 1001-1003.

Research Overview
Low-dimensional Materials: (controllable growth, fundamentally physical properties, and density functional
theory)

Our experimental results (FET,Raman, absorption spectra,TEM) and theoretical Large-size monolayer single crystalline MoS2 up to 300 µm by CVD growth.-
calculations(DFT) revealed the stronginterlayer interaction in 2D layered PtS2. - Scientific Reports, 2015
Adv. Mater., 2016

In situobservation of MoS2 inside TEM toreveal the growth dynamics. -
Nature Communication, 2016

Low-dimensional Electron Device: (field-effect transistors, memories, interconnect)

Carrier type control of 2D materials by VLSI-compatible doping method. The thickness of the Cu interconnect barrier can beeffectively reduced by x5 Department of Applied Physics
- Adv. Funct. Mater., 2016 with graphene. - ACS Nano, 2014

Integration of Energy Harvesting/ Storage Flexible/ Stretchable Devices for wearable
Device: (piezo-supercap, photovoltchormic electronics and bio-integrated electronics
supercap, & RF supercap)

Seamless integration of energy harvesting/ storagedevice, and automatic Stretchable electronic device retains itsfunctionalities during mechanical
and widely tunable opticaltransmittance for self-powered smart-window. deformation. - J. Mater. Chem. A, 2014
- ACS Nano, 2016

The Hong Kong Polytechnic University 177

Our Researchers

Department of Applied Physics

Prof. DAI Jiyan

Professor

Phone Number (852) 2766 5682
Email
Education [email protected]

Research Interests Postdoc Northwestern University, USA
ORCiD
Publication Ph.D. Chinese Academy of Sciences
H-index
Sum of the Times Cited B.Sc. Fudan University

Smart Materials, Nanomaterials, Thin Films and Ultrasonic Device

0000-0002-7720-8032

240

33

5472

Awards Publications (selected)

•• President Award in Research and Scholarly Activities, 2007 •• Peng, K. L., Lu, X., Zhan, H., J.Y. Dai et al. Broad
temperature plateau for high ZTs in heavily doped
•• Faculty Award in Research and Scholarly Activities, 2007 p-type SnSe single crystals, Energy & Environmental
Science, Vol 9, Issue 2, pp. 454-460 (2016).
•• Supervised Final Year Project student received Award
of Best Paper in Materials from the Hong Kong Institute •• Li, L., Liu, Y., Dai, J.Y., Zhu, H.X., Hong, A.J.,
of Engineering, 2006 Zhou,X.H., Ren, Z.F., Liu, J.M., Thermoelectric
property studies on CuxBi2SeS2 with nano-scale
•• BEST IN SESSION at ISTFA 2001 in Santa Clara, California, precipitates Bi2S3, Nano Energy, 12, 447 (2015).
the ASM Electronic Device Failure Analysis Society
•• Zhang, X., Zheng, Y., Liu, X., Lu, W., Dai, J., Lei, D.Y.,
Patents Macfarlane, D.R., Adv. Mater., Vol 27, 1090 (2015).

•• J.Y. Dai, S.F. Tee, C.L. Tay, E. Er, and R. Shailesh, •• Ngai Yui Chan, Meng Zhao, JianXing Huang, Kit Au,
Method for a Plan-view transmission electron Man Hon Wong, Hei Man Yao, Wei Lu, Yan Chen,
microscopy sample preparation technique for via Chung Wo Ong, Helen Lai Wa Chan and Jiyan Dai,
and contact characterization. US 6,683,304 Highly-sensitive gas sensor by the LaAlO3/SrTiO3
heterostructure with Pd Nanoparticle Surface
•• J.Y Dai, P.F. Lee and X.B. Lu, Process and appara- Modulation, Adv. Mater., 26, 5962 (2014).
tus for fabricating nano-floating gate memories and
memory made thereby. US 7,585,721B2 •• J.X. Zhang, H.R. Fu, W. Lu, J.Y. Dai and H.L.W. Chan,
Nanoscale free-standing magnetoelectric heteropillars,
•• J. Peng, C. Chao, J.Y. Dai, and H.L.W. Chan, Pi- Nanoscale 5, 6747 (2013).
ezoelectric Single crystalline thick film on silicon
wafer for Piezoelectric micro-electro-mechanical •• Au, D. F. Li, N. Y. Chan, and J. Y. Dai, Polar Liquid
systems, US Patent, US 8536665B2 Molecule Induced Transport Property Modulation
at LaAlO3/SrTiO3 Heterointerface, Adv. Mater., 24,
•• 一種複合壓電陣子及其製備方法 . 已授權 . 申請時間: 2598 (2012).
2011 年 01 月 05 日,授權時間:2014 年 12 月 31
日. 發 明人:周丹,張國峰,林國豪,陳燕,戴吉岩, •• X.S. Gao, J.M. Liu, Kit Au, and J.Y. Dai, Nanoscale
陳王麗華,申請號:201110001124.8 ferroelectric tunnel junctions based on ultrathin
BaTiO3 film and Ag nanoelectrodes, Appl. Phys.
•• 環狀陣列超聲波內窺鏡探頭及其製備方法和固定旋轉 Lett. 101, 142905-09 (2012).
裝置 . 已授權 . 申請時間:2011年05月23日,授
權時間:2014年12月10日 . 發明人:戴吉岩,張國 •• Zhang XY, Zhao X, Lai CW, J. Wang, X.G. Tang,
峰,周丹,焦逸靜,林國豪,陳燕,陳王麗華,申請 and Dai JY, Synthesis and piezoresponse of highly
號:201110132195.1 ordered Pb(Zr0.53Ti0.47)O3 nanowire arrays, Appl.
Phys. Lett. 85, 4190 (2004).
•• 旋轉超聲成像系統 , 已授權 . 申請時間:2010 年 11 月 12 日 ,•
授權時間:2013 年9月18日 . 發明人:林國豪 ,陳燕,•
戴吉岩,陳王麗華。申請號:201010542689.2

•• 基於三維超聲成像的二維陣列超聲換能器及其製備方
法,發明人:戴吉岩,方華靖,黃智文,陳燕。已授權
申請號:2014106173593

178 Research at FAST

Research Overview

Research Foci/ Projects

GRF (As PI) Photovoltaic, Spin Field Effect Transistor and Sensing Devices Based on Polar Oxide

01 Jan 2015 - 31 Dec 2017 Heterostructural Two-dimensional Electron Gas

GRF (As PI) Study of Dynamic Strain Modulation to Transport Properties of Oxide Heterostructure

01 Jan 2017 - 31 Dec 2019

Prof. Dai’s group has been devoting in developing high-performance ultrasound transducers including phase-array,
annular-array, high-frequency transducers as well as endoscopic and intravascular ultrasound transducers for medical
imaging. He has successfully finished two ITF projects in ultrasound transducers development and is running a new ITF
project for high-frequency phase-array transducer for eye and small animal imaging. He has also led a team for National
973 project for developing high-performance ultrasound transducers, and some inventions have been implemented
and licensed to industry. These efforts and pioneer works have greatly accelerated the progress of China’s medical
ultrasound imaging technology.

Functional Oxide Thin Films and Devices (ii) Multiferroic tunnelling junction and RRAM

(i) Polar liquid, UV light and gas sensing properties in the We demonstrate a success of this four-state memory in a
LaAlO3/SrTiO3 2D electron system. material system of NiFe/BaTiO3/La0.7Sr0.3MnO3 with improved
memory characteristics such as lower switching field and
With LaAlO3 surface modification by Pd nanoparticles, larger tunneling magnetoresistance (TMR). Scientific
LaAlO3/SrTiO3 (LAO/STO) interfacial two-dimensional Reports | 5:12826 | DOI: 10.1038/ srep12826
electron gas presents a giant optical switching effect with a
photoconductivity on/off ratio as high as 750% under UV light
irradiation.

Adv. Mater., 26, 5962 (2014) Department of Applied Physics
Adv. Mater., 24, 2598–2602 (2012)
ACS Nano. 22, 8673 (2013)

Ultrasound Transducers and Biomedical Imaging

PMN-PT single crystal-based array transducers, high-frequency transducers and Intravascular transducers and imaging.

The Hong Kong Polytechnic University 179

Our Researchers

Department of Applied Physics

Dr FUNG Kin Hung

Assistant Professor

Phone Number (852) 2766 5684
Email
Education [email protected]

Research Interests Postdoc. Massachusetts Institute of Technology (MIT)

ORCiD Ph.D. The Hong Kong University of Science and Technology
Publication
H-index M.Phil. The Hong Kong University of Science and Technology
Sum of the Times Cited
B.Sc. The Hong Kong University of Science and Technology

Plasmonics, Nanophotonics, Optomechanics, Topological Photonics/

Acoustics

0000-0003-0501-8843

63

17

1381

Awards and Grants (selected) Publications (selected)

•• GRF Project Grant from Hong Kong RGC •• “Coalescence of Nonreciprocal Exceptional Points
(as PI, HK$ 314K) 2017 in Magnetized PT-symmetric Systems”, Physical
Review B 97, 014428 (2018).
•• GRF Project Grant from Hong Kong RGC
(as PI,HK$ 451K) 2015 •• “Electron-beam Excited Photon Emission from Monopole
Modes of a Plasmonic Nano-disc”, Optics Letters 42,
•• Area of Excellence Project Grant from Hong Kong 3387 (2017).
RGC (as Co-I, HK$ 46.5M) 2013
•• “Chiral plasmon in gapped Dirac systems”, Physical
•• ECS Project Grant from Hong Kong RGC Review B Rapid Comm. 93, 041413(R) (2016).
(as PI,HK$ 760K) 2013
•• “Anomalous Light Scattering by Topological
•• Postgraduate Outstanding Research Award 2008 PT-symmetric Particle Arrays”, Scientific Reports 6,
38049 (2016).
•• HKUST Academic Achievement Medal 2002
•• “Plasmonic Topological Edge Plasmon Modes between
Book Chapters Diatomic Chains of Plasmonic Nanoparticles”,
Optics Express 23, 2021-2031 (2015).
•• Kin Hung Fung*, Jeffrey Chi Wai Lee, C. T.
Chan,“Chiral Photonic and Plasmonic Structures”, •• “Non-reciprocal mu-near-zero mode in PT-symmetric
in Plasmonics and Plasmonic Metamaterials, (World magnetic domains”, Physical Review B 91, 235410
Scientific, 2011), Ch2. (2015).

•• Kin Hung Fung and Nicholas X. Fang, “Plasmonics •• “Tunable light-matter interaction and the role of
and Metamaterials”, in Nanobiophotonics, hyperbolicity in graphene-hBN system”, Nano Letters
(McGraw-Hill, 2010), pp. 173-197. 15, 3172-3180 (2015).

•• Jensen Li, Kin Hung Fung, Z.Y. Liu, P. Sheng, and •• “Formation of Non-reciprocal Bands in Magnetized
C.T. Chan,“Generalizing the concept of negative Diatomic Plasmonic Chains”, Physical Review B 92,
medium to acoustic waves”, in Physics of Negative 165430 (2015).
Refraction and Negative Index Materials, (Springer,
Berlin, 2007), pp. 183-215. •• “Electron-photon scattering mediated by localized-
plasmons: A quantitative analysis by eigen-response
theory”, Physical Review B 89, 045408 (2014).

•• “Terahertz Plasmonics on Ferroelectric-Gated Graphene”,
Applied Physics Letters 102, 201118 (2013).

•• “Ultra-broadband Light Absorption by a Sawtooth
Anisotropic Metamaterial Slab”, Nano Letters 12,
1443-1447 (2012).

180 Research at FAST

Research Overview
Nanophotonics/ Plasmonics (Theory)

Phys. Rev. B (Rapid Comm.) 93, 041413(R) (2016) Department of Applied Physics
Optics Letters 41, 1644 (2016)
Phys. Rev. B 92, 165430 (2015)
Optics Express 23, 2021-2031 (2015)
Phys. Rev. B 91, 235410 (2015)
Optics Letters 38, 5232-5235 (2013)

Plasmon Enhanced Light-Matter/ Photon-Electron Interaction (Theory)

Nano Letters 11, 61-65 (2011)
Nano Letters 12, 1443-1447 (2012)
Nano Letters 12, 796-801 (2012)
Physical Review B 89, 045408 (2014)
Nano Letters 15, 3172-3180 (2015)

Nano Letters 11, 61-65 (2011)
Nano Letters 12, 1443-1447 (2012)
Nano Letters 12, 796-801 (2012)
Physical Review B 89, 045408 (2014)
Nano Letters 15, 3172-3180 (2015)

The Hong Kong Polytechnic University 181

Our Researchers

Department of Applied Physics

Prof. HAO Jianhua

Professor and Associate Head of Department

Phone Number (852) 2766 4098
Email
Education [email protected]

Research Interests Postdoc. Penn State University

ORCiD Ph.D Huazhong University of Science and Technology
Publication
H-index M.Sc. Huazhong University of Science and Technology
Sum of the Times Cited
B.Sc. Huazhong University of Science and Technology

Functional Thin-films, Two-dimensional Layered Materials &

Heterostructures, Luminescence and Phosphors for Photonic,

Energy and Biomedical Applications

0000-0002-6186-5169

237

47

7285

Awards (selected) Research Overview

•• TechConnect Global Innovation Award (USA) 2018 Functional Thin-films, Two-dimensional
Layered Materials and Heterostructures
•• Special Merit Award and Gold Medal with
Congratulations of Jury for the invention, The 45th 1. Pulsed laser deposited ferroelectric and piezoelectric
International Exhibition of Inventions of Geneva 2017 thin films and heterostructures

•• Nanoscience Research Leader Award 2016 2. Two-dimensional layered materials and devices
(Cognizure based on the publications in Scopus) 3. Coupling of smart materials to heterostructure devices

•• Faculty Award for Outstanding Performance/
Achievement in Research & Scholarly-Individual in
PolyU 2012/13

•• Most Cited Scientists in Materials Science; “Hot
Paper” and “Highly Cited Papers” (ESI)

•• Materials Research Contribution Award (Asia Pacific
Society for Materials Research)

Book Chapters Selected Publications (*corresponding author):

•• Ming-Kiu Tsang, Yuen-Ting Wong, and Jianhua Hao*, • W. Jie, X. Chen, D. Li, L. Xie, Y. Y. Hui, S. P. Lau, X. Cui,
“Upconversion nanomaterials for biodetection and J. Hao*, Layer-dependent nonlinear optical proper-
multimodal bioimaging using photoluminescence”, ties and stability of non-centrosymmetric modification
in Challa S.S.R. Kumar (Ed) Book: Nanotechnology in few-layer GaSe sheets. Angew. Chem. Int. Ed. 54,
Characterization Tools for Biosensing & Medical 1185 (2015).
Diagnosis, chap. 6, page 249-275 (Springer Nature)
(2018). • G. Bai, S. Yuan, Y. Zhao, Z. Yang, S. Y. Choi, Y. Chai,
S. F. Yu, S. P. Lau, J. Hao*, “2D layered materials of
•• Wenjing Jie and Jianhua Hao*, “Two-Dimensional rare-earth Er-doped MoS2 with NIR-to-NIR down- and
Layered Gallium Selenide: Preparation, Properties, up-conversion photoluminescence”, Adv. Mater., 28,
and Applications”, in Ashutosh Tiwari and Mikael 7472 (2016).
Syvajarvi (Eds) Book: Advanced Materials, chap. 1,
page 3-36 (John Wiley & Sons) (2016). • S. Yuan, Z. Yang, C. Xie, F. Yan, J. Dai, S. P. Lau, H.
L.W. Chan, J Hao*, “Ferroelectric-driven performance
182 Research at FAST enhancement of graphene field-effect transistor
based on vertical tunnelling heterostructures”, Adv.
Mater. 28, 10048 (2016).

• Z. Yang, W. Jie, C.-H. Mak, S. Lin, H. Lin, X. Yang,
F. Yan, S. P. Lau, J. Hao*, “Wafer-scale synthesis of
high-quality semiconducting two-dimensional layered
InSe with broadband photoresponse”, ACS Nano 11,
4225 (2017).

• W. Jie, Z. Yang, F. Zhang, G. Bai, C. W. Leung, Department of Applied Physics
J. Hao*, “Observation of room-temperature magne-
toresistance in monolayer MoS2 by ferromagnetic
gating”, ACS Nano 11, 6950 (2017).

• M.-C. Wong, L. Chen, G. Bai, L.-B. Huang, J. Hao*,
“Temporal and remote tuning of piezophotonic
effect-induced luminescence and color gamut via
modulating magnetic field”, Adv. Mater. 29, 1701945
(2017).

• J. Hao, W. Huang, Z. Yang, Semiconductor gallium
arsenide compatible epitaxial ferroelectric devices for
microwave tunable application. US Patent, Granted
Patent No. US 8,980,648 B1.

Luminescence and Phosphors for Photonic, Energy and Biomedical Applications

1. Stimuli responsive luminescence and multifunctional phosphors
2. Upconversion luminescence nanomaterials for multi-modal bioimaging and biosensor applications
3. Mechanical energy harvesting applications

Selected Publications (*corresponding author):
•• M.-K. Tsang, G. Bai, J. Hao*, Stimuli responsive upconversion luminescence nanomaterials and films for various applications.

Chem. Soc. Rev. 44, 1585 (2015).
•• M.-C. Wong, L. Chen, M.-K. Tsang, Y. Zhang, J. Hao*, Magnetic-induced luminescence from flexible composite laminates by

coupling magnetic field to piezophotonic effect. Adv. Mater. 27, 4488 (2015).
•• L.-B. Huang, G. Bai, M.-C. Wong, Z. Yang, W. Xu, J. Hao*, Magnetic-assisted noncontact triboelectric nanogenerator

converting mechanical energy into electricity and light emissions. Adv. Mater. 28, 2744 (2016).
•• G. Bai, M.-K. Tsang, J. Hao*, “Luminescent ions in advanced composite materials for multifunctional applications”,

Adv. Funct. Mater. 26, 6330 (2016).
•• W. Xu, L.-B. Huang, J. Hao*, “Fully self-healing and shape-tailorable triboelectric nanogenerators based on healable polymer

and magnetic-assisted electrode”, Nano Energy 40, 399 (2017).
•• W. Xu, L.-B. Huang, M.-C. Wong, L. Chen, G. Bai, J. Hao*, “Environmentally friendly hydrogel-based triboelectric

nanogenerators for versatile energy harvesting and self-powered sensors”, Adv. Energy Mater. 7, 1601529 (2017).
•• J. Hao, Z. Wang, S. Zeng, H. L. W. Chan, Water-soluble nanoparticles exhibiting up-conversion luminescence, and a method

of one-pot synthesis thereof. US Patent, Granted Patent No. US 8,999,506 B2.

Featured on Journal Covers

The Hong Kong Polytechnic University 183

Our Researchers

Department of Applied Physics

Dr HUANG Haitao

Associate Professor

Phone Number (852) 2766 5694
Email
Education [email protected]

Research Interests Ph.D Nanyang Technological University
ORCiD
Publication M.Phil. Shanghai Institute of Metallurgy
H-index
Sum of the Times Cited Double B.Sc. Shanghai Jiao Tong University

Nanostructured Energy Materials, Ferroelectrics for Energy

0000-0002-3861-2702

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41

5318

Awards (selected) •• J.Lin, M.Guo, C.T.Yip, W.Lu, G.Zhang, X.Liu,
L.Zhou, X.Chen* and H.Huang*, “High Temperature
•• Science and Technology Award, (2nd Class), the Crystallization of Free-Standing Anatase TiO2
Ministry of Land and Resources of the People’s Nanotube Membranes for High Efficiency Dye-
Republic of China, 2017 Sensitized Solar Cells”, Adv.Funct.Mater. 23, 5952
(2013).
•• Outstanding Achievement Award, Asia Pacific Society
for Materials Research, 2014 •• G.Zhang*, W.Li, K.Xie, F.Yu and H.Huang*, “A
One-Step and Binder-Free Method to Fabricate
Publications (selected) Hierarchical Nickel-Based Supercapacitor Electrodes
with Excellent Performance”, Adv.Funct.Mater. 23,
•• Y.Chen, X.Li, K.Park, W.Lu, C.Wang, W.Xue, 3675 (2013).
F.Yang, J.Zhou, L.Suo, T.Lin, H.Huang*, J.Li*, and
J.B.Goodenough*, “Nitrogen-Doped Carbon for •• M.Guo, K.Xie, J.Lin, Z.Yong, C.T.Yip, L.Zhou,
Sodium-Ion Battery Anode by Self-Etching and Y.Wang and H.Huang*, “Design and Coupling of
Graphitization of Bimetallic MOF-Based Nanocom- Multifunctional TiO2 Nanotube Photonic Crystal to
posite”, Chem 3, 152 (2017). Nanocrystalline Titania Layer as Semi-Transparent
Photoanode for Dye-Sensitized Solar Cell”, Energy
•• M.Xu, L.Fei, W.Zhang, T.Li, W.Lu, N.Zhang, Y.Lai*, Environ. Sci. 5, 9881 (2012).
Z.Zhang, J.Fang, K.Zhang, J.Li and H.Huang*,
“Tailoring Anisotropic Li-Ion Transport Tunnels •• C.T.Yip, H.Huang*, L.Zhou*, K.Xie, Y.Wang, T.Feng,
on Orthogonally Arranged Li-Rich Layered Oxide J.Li and W.Y.Tam, “Direct and Seamless Coupling
Nanoplates Toward High-Performance Li-Ion Bat- of TiO2 Nanotube Photonic Crystal to Dye Sensitized
teries”, Nano Lett. 17, 1670 (2017). Solar Cell: A Single-Step Approach”, Adv.Mater.
23, 5624 (2011).
•• Y.Liu, N.Fu, G.Zhang, M.Xu, W.Lu, L.Zhou and
H.Huang*, “Design of Hierarchical Ni-Co@Ni-Co •• H.Huang*, “Solar Energy: Ferroelectric Photovoltaics”,
Layered Double Hydroxide Core-Shell Structured Nature Photonics 4, 134 (2010).
Nanotube Array for High-Performance Flexible All-
Solid-State Battery-Type Supercapacitors”, Adv.
Funct.Mater. 27, 1605307 (2017).

•• Y.Chen, X.Li, K.Park, L.Zhou, H.Huang*, Y.-W.
Mai and J.B.Goodenough*, “Hollow Nanotubes of
N-Doped Carbon on CoS”, Angew.Chem.Int.Ed.
55, 15831 (2016).

•• C.T.Yip, X.Liu, Y.Hou, W.Xie, J.He, S.Schlücker,
D.Lei and H.Huang, “Strong Competition Between
Electromagnetic Enhancement and Surface-Ener-
gy-Transfer Induced Quenching in Plasmonic Dye-
Sensitized Solar Cells: A Generic yet Controllable
Effect”, Nano Energy 26, 297 (2016).

184 Research at FAST

Research Overview Department of Applied Physics

My current research interests include materials for electrochemical energy storage and conversion, such as high performance
electrochemical supercapacitors, rechargeable batteries and solar cells. They also include the emerging ferro-energy materials,
which are ferroelectric materials for energy storage and conversion applications, such as high energy-density physical
capacitors, electrocaloric energy conversion, and ferro-catalysis.

Solar Cells

TiO2 nanotube array for enhanced electron transport and photon management; Low temperature processed TiO2 for flexible solar
cells.

Electrochemical Energy Storage (Supercapacitors and Batteries)

Electrospinning of electrode materials; Wearable supercapacitors

Ferroenergy

Electrical energy storage; Electrocaloric effect; Ferroelectric photovoltaic

The Hong Kong Polytechnic University 185

Our Researchers

Department of Applied Physics

Prof. KWOK Kin Wing

Professor
Associate Dean of Faculty of Applied Science and Textiles

Phone Number (852) 2766 5667
Email
Education [email protected]

Research Interests Ph.D. The Hong Kong Polytechnic University

ORCiD M.Phil. The Chinese University of Hong Kong
Publication
H-index B.Sc. The Chinese University of Hong Kong
Sum of the Times Cited
Processing, Characterization and Applications of Ferroelectric

Materials, Electro-optic Materials, Photoluminescence Materials

0000-0001-6742-4180

174

34

3571

Patents Publications (selected)

•• X.X. Wang, K.W. Kwok, H.L.W. Chan and S.H. •• Hailing Sun, Xiao Wu, Dengfeng Peng and
Choy, “Piezoelectric Ceramic Composition and K.W. Kwok, “Room temperature large and reversible
the Method for Preparing the Same”, US Patent, modulation of photoluminescence by in-situ electric
No. US 7,494,601 field in ergodic relaxor ferroelectrics”, ACS Applied
Materials & Interfaces 9 (2017) 34042-34049.
•• H.L.W. Chan, T.Y. Lam, C. Chen and K.W. Kwok, “Method
and Apparatus for Measuring Oscillation Amplitude •• Hailing Sun, Xiao Wu, Tat Hang Chung and K.W. Kwok,
of an Ultrasonic Bonding Tool”, US Patent, No. US “In-situ electric field-induced modulation of photo-
7,819,013 luminescence in Pr-doped Ba0.85Ca0.15Ti0.90Zr0.10O3
Lead-Free Ceramics”, Scientific Reports 6 (2016)
•• D.M. Lin, K.W. Kwok and H.L.W. Chan, “鈮酸鈉 28677.
甲鋯 鈦酸鋇無鉛壓電陶瓷組合物”, Chinese Patent,
No. ZL200710006787.2 •• S.B. Lu, Z.K. Xu, K.W. Kwok and H.L.W. Chan, “Hot- stage
transmission electron microscopy study of (Na,K)
Book Chapters NbO3 based lead-free piezoceramics”, Applied
Physics Letters 105 (2014) 042904.
•• K.W. Kwok, T. Lee, S.H. Choy and H.L.W. Chan,
“Lead-free piezoelectric transducers for microelectronic •• Faliang Li and K.W. Kwok, “Fabrication of transparent
wirebonding applications” Chapter 8, Piezoelectric electro-optic (K0.5Na0.5)1-xLixNb1-xBixO3 lead-free ceramics”,
Ceramics, Edited by Ernesto Suaste Gomez SCIYO. Journal of the European Ceramic Society 33 (2013)
123-130.
•• K.W. Kwok and Dunmin Lin, “Preparation and pi-
ezoelectric properties of K0.5Na0.5NbO3-based •• Xiao Wu, K.W. Kwok and Faliang Li, “Upconversion
lead-free piezoelectric ceramics”, Chapter 3, Fer- fluorescence of sol-gel-derived Er-doped KNN
roelectrics: New Research, Edited by X.L. Huang ceramics”, Journal of Alloys and Compounds 580
and S.L. Ma, NOVA Science Publishers Inc. (2013) 88-92.

•• D.Y. Wang, Dunmin Lin, K.W. Kwok, N.Y. Chan,
J.Y. Dai, S. Li and H.L.W. Chan, “Ferroelectric,
piezoelectric, and leakage current properties of
(K0.48Na0.48Li )0.04 (Nb0.775Ta )0.225 O3 thin films grown
by pulsed laser deposition”, Applied Physics
Letters 98 (2011) 022902.

•• C.G. Xu, Dunmin Lin and K.W. Kwok, “Structure,
electrical properties and depolarization temperature
of (Bi0.5Na0.5)TiO3-BaTiO3 lead-free piezoelectric of
ceramics”, Solid State Sciences 10 (2008) 934-940.

186 Research at FAST

Research Overview Department of Applied Physics
Lead-free Transparent Electro-optical (K0.5Na0.5)1-xLixNb1-xBixO3 Ceramics

The first lead-free electro-optic (EO) polycrystalline ceramic with excellent transparency and strong linear electro-optic
response, which are even better than the lead-based counterparts that are widely used in industries for various optoelectronic
applications.

Fabrication:
Conventional atmospheric sintering techniques
Features:
Dense & fine-grained structure
Nearly cubic crystal structure
Relaxor-like ferroelectrics
Properties:
Strong linear electro-optic response (rc ~ 130 - 200 pm/V)
Good ferroelectric and piezoelectric properties (d33 ~ 80 pC/N)

Ferroelectric Ceramics with Strong and Tunable Photoluminescence Response

Via taking the advantages of the characteristics of ferroelectric materials such as the switchable spontaneous polarization,
phase transformation, ergodicity and electric field-induced strains, we have successfully realized real-time and reversible
modulation of photoluminescence by in situ electric field in lead-free ferroelectric ceramics at room temperature. The
physical mechanism and the interplay process between the electric field and photoluminescence have also be elucidated
in detail based on the in situ structural investigation.

Large and tunable photoluminescence responses of Eu−BNT6BT relaxor
subject to a biased ac E field varying sinusoidally between 0 and 7 kV/
mm for cycles.

Reversible lattice distortion, strain and crystal deformation of Eu-BNT6BT
relaxor induced by in situ electric field.

The Hong Kong Polytechnic University 187

Our Researchers

Department of Applied Physics

Dr LAM Chi Hang

Associate Professor

Phone Number 852) 2766 5681
Email
Education [email protected]

Research Interests Postdoc. Yale University

ORCiD Ph.D. The University of Michigan
Publication
H-index B.Sc. The University of Hong Kong
Sum of the Times Cited
Glass Transition, Glassy Polymer Nano-films, Quantum Information,

Open Quantum Systems, 2D Materials, Surface Physics

0000-0002-0476-1857

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Journal Publication Summary 2D Materials and Surface Physics:

•• 2 in Science, 7 in Physical Review Letters, 24 in •• Robust Intrinsic Ferromagnetism and Half Semi-
Physical Review, 43 in other journals conductivity in Stable Two-Dimensional Single-Layer
Chromium Trihalides, Wei-Bing Zhang, Qian Qu,
Publications (selected) Peng Zhu, Chi-Hang Lam, Journal of Materials
Chemistry C 3, 12457 (2015).
Glass Transition and Glassy Polymer Nano-films:
•• Formation mechanism of bound states in graphene
•• Dynamic facilitation theory of glassy dynamics point contacts, H.Y. Deng, K. Wakabayashi and
based on pair-interactions of hopping strings, C.-H. Lam, Physical Review B 89, 045423 (2014).
C.H. Lam and O.K.C. Tsui, arXiv:1508.03153 (2015).
•• Island, pit and groove formation in strained
•• Surface mobility of Glasses, F. Chen, C.H. Lam, heteroepitaxy, M.T. Lung, C.-H. Lam, and L.M. Sander,
and O.K.C. Tsui, Science 343, 975 (2014). Physical Review Letters 95, 086102 (2005).

•• Crossover to Surface flow in supercooled unentangled
polymer films, C.H. Lam and O.K.C. Tsui,Physical
Review E 88, 042604 (2013).

•• Glass Transition Dynamics and Surface Layer Mobility
in Unentangled Polystyrene Films, Z. Yang, Y. Fujii,
F.K. Lee, C.H. Lam, and O.K. C. Tsui, Science 328,
1676 (2010).

Open Quantum Systems:

•• Higher-order solutions to non-Markovian quantum
dynamics via hierarchical functional derivative,
Da-Wei Luo, Chi-Hang Lam, Lian-Ao Wu, Ting Yu,
Hai-Qing Lin, and J.Q. You, Physical Review A 92,
022119 (2015).

•• Approach to solving spin-boson dynamics via non
-Markovian quantum trajectories, Zeng-Zhao Li,
Cho-Tung Yip, Hai-Yao Deng, Mi Chen, Ting Yu, J.
Q. You, and Chi-Hang Lam, Physical Review A 90,
022122 (2014).

188 Research at FAST

Research Overview

Many liquids can be quenched into the glassy states when super-cooled rapidly. We study the fundamental nature of the glass
transition focusing on a dynamic facilitation behavior in which defects in the form of voids aid the motions of each other. Tech-
niques including molecular dynamics simulations, lattice model simulations, random-tree theoretical analysis, and colloidal
fluid experiments are employed. Surface enhanced dynamics and substrate effects in slippage of polymer nano-films are also
studied.

Quantum systems in practice are affected by the environmental heat bath and other disturbances forming open quantum
systems. We study the effectiveness of control methods of quantum devices in the presence of heat baths using methods such
as quantum state diffusion equations and quantum Langevin equations. Numerical approaches for efficient solution of quantum
state diffusion equations are developed and studied.

By performing computations based on density functional theory, we have identified two-dimensional materials with intrinsic
ferromagnetic properties. We also study electronic and spin-dependent transport properties in other materials such as blue
phosphorous.

Theory of Glass Transition Bead-spring model of glassy polymer Trajectories of 6 particles during
pair-interaction of voids
•• Slow dynamics in glass phase explained by voids isolated
and trapped by rugged energy landscape

•• Low-temperature dynamics found to be dominated by
pair-interaction between void pathways

•• Studied using classical molecular dynamics simulations,
lattice gas simulations, colloidal experiments, mean field
theory, and percolation theory on networks

Suppressed Glass Transition in Polymer Nano-films Department of Applied Physics

•• Liquid/glass phase identified by Arrhenius/ super-Arrhenius Dependence of polystyrene viscosity on temperature and film thickness (in nm)
temperature dependence of polymer viscosity

•• Unentangled polystyrene nano-films annealed while surface
morphological evolution observed

•• Viscosity in nano-film measured from speed of morphological
evolution

•• Liquid polymer layer thinner than 2 nm found on surface of
glassy polymer

•• Studied using atomic force microscopy, stochastic surface
evolution equation, and classical molecular dynamics sim-
ulations

Quantum Information and Open Quantum Systems

•• Quantum information encoded in qubit should preferably
be robust against interference from surrounding heat bath
(i.e. environment)

•• System (e.g. qubit) + environment = open quantum system
•• Accurate numerical approaches for exact dynamics of

open quantum systems developed and applied to the
Spin-Boson model
•• Method based on quantum state diffusion equations and
quantum master equations

Time dependence of qubit state for various thermal bath properties

The Hong Kong Polytechnic University 189

Our Researchers

Department of Applied Physics

Prof. LAU Shu Ping

Professor and Head of Department

Phone Number (852) 2766 5679
Email
Education [email protected]

Research Interests Ph.D. University of Wales Swansea

ORCiD B.Sc. The Polytechnic of North London
Publication
H-index Optoelectronic Properties, Two-dimensional Materials, Graphene,
Sum of the Times Cited
Graphene Quantum Dots, MoS2, Black Phosphorus
0000-0002-5315-8472

344

49

10069

Awards and Honours •• Y.Y. Li, Z. Hu, S.H. Lin, S.K. Lai, W. Ji, S.P. Lau, “Giant
Anisotropic Raman Response of Encapsulated
•• Silver Prize and Special Merit Award at the Seoul Ultrathin Black Phosphorus by Uniaxial Strain”,
International Invention Fair (2015) Advanced Functional Materials 27 (2017) 1600986.

•• Nanyang Award for Research and Innovation (2006) •• S. Lin, Y.S. Chui, S.P. Lau, Liquid-phase exfoliation
of black phosphorus and its applications, FlatChem
Patents 2 (2017),15-37.

•• S.P. Lau, J.S. Qian, “Improved MnO2 anode for Li-ion Five highly cited papers:
and Na-ion batteries”, US patent, filed in May 2017.
•• Y.Y. Li, Z. Hu, S.H. Lin, S.K. Lai, W. Ji, S.P. Lau, “Giant
•• S.P. Lau, J.S. Qian, J.K. Yuan, “Method for prepar- Anisotropic Raman Response of Encapsulated
ing aqueous MnO2 ink and capacitive energy storage Ultrathin Black Phosphorus by Uniaxial Strain”,
devices comprising MnO2”, US Patent, filed in March Advanced Functional Materials 27 (2017) 1600986.
2017.
•• Y. Wang, R. Fullon, M. Acerce, C.E. Petoukhoff, J.
•• S.P. Lau, M. Cholewa, G-C. Yi, J.K. Yoo, A.P. Burden, Yang, C. Chen, S. Du, S.K. Lai, S.P. Lau, D. Voiry,
L. Huang, X.Y. Gao, T.S.A. Wee, H.O. Moser, “Radiation D. O’Carroll, G. Gupta, A. D. Mohite, S. Zhang, H.
detector having coated nanostructure and method”, Zhou, M. Chhowalla, “Solution-Processed MoS2/
US patent no. 7388201, granted on 18 June 2008. Organolead trihalide perovskite photodetectors”,
Advanced Materials 29 (2017) 1603995.
Publications (selected)
•• L.B. Tang, R.B. Ji, X.M. Li, G.X. Bai, C.P. Liu, J.H.
Five recent papers: Hao, J.Y. Lin, H.X. Jiang, K.S. Teng, Z.B. Yang,
S.P. Lau, “Deep Ultraviolet to Near-Infrared Emission
•• S.H. Lin, Y. Liu, Z.X. Hu. W. Lu, C.H. Mak, L.H. and Photoresponse in Layered N-Doped Graphene
Zeng, J. Zhao, Y.Y. Li, F. Yan, Y.H. Tsang, X.M. Quantum Dots”, ACS Nano 8 (2014) 6312-6320.
Zhang, S.P. Lau, “Tunable active edge sites in
PtSe2 films towards hydrogen evolution reaction”, •• Y.Y. Hui, X. Liu, W. Jie, N.Y. Chan, J. Hao, Y.T. Hsu,
Nano Energy 42 (2017) 26-33. L. J. Li, W. Guo, S. P. Lau, “Exceptional Tunability
of Band Energy in a Compressively Strained Trilayer
•• C.P. Lee, K.Y. Lai, C.A. Lin, C.T. Li, K.C. Ho, C.I. MoS2 Sheet”, ACS Nano 7 (2013) 7126-7130.
Wu, S.P. Lau, J.H. He, “A paper-based electrode
using a graphene dot/PEDOT:PSS composite for •• L.B. Tang, R.B. Ji, X. K. Cao, J.Y. Lin, H.X. Jiang,
flexible solar cells”, Nano Energy 36 (2017), 260-267. X.M. Li, C.M. Luk, S.J. Zeng, J.H. Hao and S. P. Lau,
“Deep Ultraviolet Photoluminescence of Water-Soluble
•• M.L. Tsai, D.S. Tsai, L.B. Tang, L.J. Chen, S.P. Lau, Self-Passivated Graphene Quantum Dots”, ACS
J.H. He, “Omnidirectional harvesting of weak light Nano 6 (2012) 5102-5110.
using a graphene quantum dot-modified organic/
silicon hybrid device”, ACS Nano 11 (2017) 4565-4570.

190 Research at FAST

Research Overview Department of Applied Physics

Prof. Lau’s primary research focus is in the area of nanoscale semiconductor materials including 2D materials and quantum
dots. He has made significant and pioneering contributions to the material growth and photonic device fabrication, fundamental
understanding, and practical applications of 2D materials and quantum dots.

Current Research Projects

•• GRF: Strain-engineered atomically thin transition metal dichalcogenides for solar energy funnels
•• GRF: Anisotropic strain engineering in atomically thin black phosphorus
•• GRF: Pulsed laser deposited amorphous black phosphorus field effect transistors and its heterostructures

Ultrabroad Band Graphene Quantum Dots (GQDs)

•• Emission of GQDs can be tuned effectively by doping Cl, S and N
•• N-GQDs exhibit deep UV to NIR emission and photoresponse

Strain Engineering in Two-dimensional Layered Materials

•• PMN-PT substrate could be an excellent platform to study a wide-range of 2D materials
•• Patterned substrates could be an effect way to induced large strain to 2D materials
•• Giant anisotropic Raman response in BP

The Hong Kong Polytechnic University 191

Our Researchers

Department of Applied Physics

Dr LEI Dangyuan

Assistant Professor

Phone Number (852) 2766 5691
Email [email protected]
Education Postdoc. Imperial College London
Ph.D. Imperial College London
Research Interests MPhil. The Chinese University of Hong Kong
B.Sc. Northwest University
ORCiD Nanophotonics, Nanoplasmonics, Metamaterials, Nonlinear Optics,
Publication Optical Chirality, Surface-enhanced Raman Scattering,
H-index 2D Materials-based Photonics
Sum of the Times Cited 0000-0002-8963-0193
88
26
2032

Publication Metrics Book Chapters

•• 30 index >10 publications in Nature Communications •• D. Y. Lei, “Hierarchical Porous Plasmonic Nanostructures
and Advanced Materials etc. as New SERS substrates with Ultrahigh Reproducibility
and Sensitivity” in Recent Developments in Plasmon
•• One Hot Paper (top 0.1% in the academic field of -Supported Raman Spectroscopy: 45 years of Enhanced
Materials Science) and four Highly Cited Paper (top Raman Signals, World Scientific Publishing (UK) Ltd.,
1% in the academic field of Materials Science/ London 2018.
Physics) by Essential Science Indicators in their
publication year •• H. C. Ong, D. Y. Lei, et al., “ZnO Platforms for Enhanced
Directional Fluorescence Applications” in Metal-Enhanced
•• Four publications reviewed or highlighted by Science Fluorescence, John Wiley & Sons, Inc., 2010.
and Nature Materials (twice)
Publications (selected)
•• “Best of 2010” paper in New Journal of Physics and
IOP Select Article by Editor •• “Metal-substrate-mediated plasmon hybridization in a
nanoparticle dimer for photoluminescence linewidth
Awards shrinking and intensity enhancement”, ACS Nano 11,
3067-3080 (2017).
•• Institute of Physics Journal of Optics “Emerging Leaders”
themed issue, 2018 •• “Plasmonic enhancement and polarization dependence
of nonlinear upconversion emissions from single Au
•• Key Technology Partner Visiting Fellow of University of nanorod@SiO2@CaF2:Yb3+,Er3+ hybrid core-shell-
Technology, Sydney, 2017 satellite nanostructures”, Light: Science & Applications
6, e16127 (2017).
•• JMCC Emerging Investigators: 2016’s Rising Stars of
Materials Chemistry Research, 2016 •• “Plasmonic dual-enhancement and precise color tuning
of gold nanorod@SiO2 coupled core-shell-shell
•• Royal Society International Exchange award (£12000 upconversion nanocrystals”, Advanced Functional
to share with UCL), 2016 Materials 27, 1701842 (2017).

•• Early Career Grants award (2nd level), The Hong Kong •• “Panchromatic thin perovskite solar cells with broadband
Research Grants Council, 2013 plasmonic absorption enhancement and efficient
light scattering management by Au@Ag core-shell
•• Anne Thorne PhD Thesis Prize, Imperial College London, nanocuboids”, Nano Energy 41, 654-664 (2017).
2012
•• “Interband absorption enhanced optical activity in dicrete
•• Deputy Rector’s Award, Imperial College London, Au@Ag core-shell nanocuboids: Probing extended
2008-2011 helical conformation of chemisorbed cysteine molecules”,
Angew Chemie International Edition 129, 1303-1308
(2017).

192 Research at FAST

Research Overview

Focusing on nanophotonics and nanomaterials studies, with particular interest in suface plasmon-enhanced light-matter
interaction at the nanoscale and its applications in energy harvesting, optoelectronic devices, biochemical sensing, biomedical
imaging, and environmental monitoring and remediation (see the research strategy below).

Schematics: Hybrid plasmonic upconversion nanostructures as efficient
nonlinear fluorescence probes with polarized nonlinear upconversion
emissions.

Nonlinear Plasmonics and Photonics for Bioimaging and Optoelectronics

Relevant corresponding-authored publications: •• Nano Energy 26, 297-304 (2016) Department of Applied Physics
•• ACS Photonics, Article ASAP (2018) •• ACS Nano 10, 1442-1453 (2016)
•• ACS Photonics 5, 1676-1684 (2018) •• Nanoscale 8, 7199-7126 (2016)
•• ACS Photonics, DOI: 10.1021/acsphotonics.7b01457 (2018) •• ACS Applied Materials & Interfaces 8, 472-479 (2016)
•• Journal of Optics 20, 024010 (2018) •• Journal of Materials Chemistry C 4, 3956-3962 (2016)
•• Nano Energy 41, 654-664 (2017) •• ACS Applied Materials & Interfaces 7, 23496-23500 (2015)
•• Advanced Functional Materials 27, 1701842 (2017) •• Scientific Reports 5, 15235 (2015)
•• Journal of Materials Chemistry C 5, 11239-11245 (2017) •• ACS Photonics 2, 1306-1313 (2015)
•• Physical Review B 96, 035430 (2017) •• Scientific Reports 5, 11552 (2015)
•• ACS Nano 11, 3067-3080 (2017) •• Nanoscale 6, 1311-1317 (2014)
•• Light: Science & Applications 6, e1627 (2017) •• Advanced Optical Materials 2, 56-64 (2014)
•• ACS Nano 10, 11105-11114 (2016) •• Small 10, 576-583 (2014)
•• ACS Photonics 3, 2434-2444 (2016) •• Nanoscale 5, 9129-9133 (2013)
•• Chemistry of Materials 28, 7807-7815 (2016)
•• Journal of Materials Chemistry C 4, 8822-8828 (2016)

Chiral Plasmonics and Surface-enhanced Raman Scattering for Biosensing & Environment Monitoring

Schematics: The discrete Au@Ag core-shell nanocuboids capped with Schematics: Hierarchical porous plasmonic metamaterials for reproducible
cysteine molecules exhibit two bisignate circular dichroism resonances in ultrasensitive surface-enhanced Raman spectroscopy pH.
the UV region, probing the formation of extended helical networks among
neighboring cysteine molecules at low pH.

Relevant corresponding-authored publications: •• Nanoscale 280, 706-712 (2014)
•• Advanced Functional Materials, in press (2018) •• Applied Surface Science 301, 351-357 (2014)
•• Angew Chemie International Edition 129, 1303-1308 (2017) •• Journal of Applied Physics 114, 124305 (2013)
•• Advanced Functional Materials 26, 7807-7816 (2016) •• Applied Surface Science 287, 404-410 (2013)
•• Optics Express 24, 19517-19530 (2016) •• Nano Today 8, 480-493 (2013)
•• Advanced Materials 27, 1090-1096 (2015)
•• ACS Nano 8, 9188-9198 (2014)
•• Journal of Hazardous Materials 280, 706-712 (2014)

The Hong Kong Polytechnic University 193

Our Researchers

Department of Applied Physics

Dr LEUNG Chi Wah Dennis

Associate Professor and Associate Head of Department

Phone Number (852) 2766 5670
Email [email protected]
Education Ph.D. University of Cambridge
B.Eng. The University of Hong Kong
Research Interests Magnetism and Spintronics, Nanofabrication Techniques,
Memory Technology
ORCiD 0000-0003-0083-6273
Publication 144
H-index 22
Sum of the Times Cited 1811

Awards and Honours Publications (selected)

•• QS Reimagine Education 2016 Gold Award (Asia) (2016) •• ‘A ferroelectric relaxor polymer-enhanced p-type WSe2
transistor’, C. Yin, X.D. Wang, Y. Chen, D. Li, T. Lin, S.
•• Faculty Award for Outstanding Performance/ Achievement Sun, H. Shen, P.Y. Du, J.L. Sun, X.J. Meng, J.H. Chu,
2014/15 in Teaching (Team Award), PolyU (2015) H.F. Wong, C.W. Leung, Z.R. Wang and J.L. Wang,
Nanoscale, 10, 1727 (2018).
•• Croucher Foundation Postdoctoral Research Fellow (2003)
•• ‘Observation of Room-Temperature Magnetoresistance
Professional Activities in Monolayer MoS2 by Ferromagnetic Gating’, W.J. Jie,
Z.B. Yang, F. Zhang, G.X. Bai, C.W. Leung and J.H.
•• Editor, Proceedings for 2018 IEEE International Magnetics Hao, ACS Nano, 11, 6950 (2017).
Conference (INTERMAG), Singapore (Apr 2017)
•• ‘Atomic-scale mechanism on nucleation and growth of
•• Editor, Proceedings for 2017 IEEE International Magnetics Mo2C nanoparticles revealed by in-situ transmission
Conference (INTERMAG), Dublin, Ireland (Apr 2017) electron microscopy’, L.F. Fei, S.M. Ng, W. Lu, M. Xu,
L.L. Shu, W.B. Zhang, Z.H. Yong, T.Y. Sun, C.H. Lam,
•• Editor, Proceedings for 13th Joint MMM-Intermag C.W. Leung, C.L. Mak and Y. Wang, Nano. Lett. 16,
Conference, San Diego, USA (Jan 2016) 7875 (2016).

•• Chairperson, IEEE Magnetics Society (Hong Kong Chapter), •• ‘ITO/Au/ITO sandwich structure for near-infrared
2015 – now plasmonics’, X. Fang, C.L. Mak, J.Y. Dai, K. Li, H. Ye
and C.W. Leung, ACS Appl. Mater. Inter., 6, 11543
•• Program Chair, IEEE Magnetics Society Symposium on (2014).
Magnetism and Magnetic Technologies, Hong Kong, P.R.
China (Aug 2014) •• ‘Enhanced charge extraction in organic solar cells
through electron accumulation effects induced by metal
•• Co-organizer, International Workshop on Spin and Mag- nanoparticles’, F.X. Xie, W.C.H. Choy, W.E.I. Sha, D.
netization Dynamics, Hong Kong, P.R. China (Dec 2012) Zhang, S.Q. Zhang, X.C. Li, C.W. Leung and J.H.
Hou, Energy Environ. Sci., 6, 3372 (2013).
Community Services
•• ‘A Polyferroplatinyne Precursor for the Rapid
•• Member, School Management Committee, N.T. Heung Yee Fabrication of L10-FePt-type Bit Patterned Media by
Kuk Yuen Long District Secondary School, Hong Kong Nanoimprint Lithography’, Q.C. Dong, G.J. Li, C.L.
(2013 – now) Ho, M. Faisal, C.W. Leung, P.W.T. Pong, K. Liu, B.Z.
Tang, I. Manners and W.Y. Wong, Adv. Mater. 24, 1034
•• Adjudicator, Joint School Science Competition, Hong (2012).
Kong (2012 – now)
•• ‘Exchange bias and blocking temperature in Co/ FeMn/
CuNi trilayers’, M.G. Blamire, M. Ali, C.W. Leung, C.H.
Marrows and B.J. Hickey, Phys. Rev. Lett., 98, 217202
(2007).

194 Research at FAST

Research Overview

Magnetism and Spintronics in Thin Films and Heterostructures

•• Magnetism of metallic films and multilayered structures, which can be used for data storage and field sensing applications
•• Exchange bias behaviour in ferromagnet/ antiferromagnet interfaces
•• Control of magnetism in dilute magnetic oxides by resistive switching

Nanopattern and Nanodevice Fabrication Techniques Sci. Rep., 5, 12826 (2015)
PRL, 98, 217202 (2007)
Top-down Approaches: APL, 104, 062409 (2014)
APL 102, 102112 (2013)
• Focused ion beam patterning: 3D etching permits PRB, 72, 212409 (2005)
direct-writing of sophisticated nanostructures
Nanotechnology, 15, 786 (2004)
• Soft-mold nanoimprint lithography: moderate conditions J. Nanosci. Nanotech., 12, 6315 (2012)
(pressure and temperature) for preparing nanopatterns Adv. Mater., 24, 1034 (2012)
over extended regions. Applications in photonics, plasmonics, J. Phys. Chem. C, 116, 532 (2012)
photovoltaics, and bit-patterned media
Department of Applied Physics
Bottom-up Synthesis:

•• Aluminum anodization: ordered high aspect-ratio nanopore
templates with tunable pore sizes by anodization voltage;
suitable for nanowire growth and photonics catalytic
applications

•• Further control of pore arrangement by simple pre-imprinting
steps for tailored pore lattice geometries

Novel Storage Media for Abundant Data Computing

•• Perovskite films with multistate resistive switching: Demonstration of nonvolatile resistance states at multiple values upon
various electric field values. Potential for dramatic increase in data storage capacity

•• Novel precursor copolymers for synthesis of hard magnetic alloys. With simple nanoimprinting and pyrolysis steps, bit-patterned
media can be prepared

•• Organic Thin Film Transistors with embedded metal nanoparticles for enhanced charge retention characteristics in flexible
devices

PRB, 76, 075122 (2007)
AP, 104, 123705 (2008)
Adv. Funct. Mater., 24, 857 (2014)
Org. Electron., 11, 990 (2010)

The Hong Kong Polytechnic University 195

Our Researchers

Department of Applied Physics

Dr MAK Chee Leung

Associate Professor

Phone Number (852) 2766 5669
Email [email protected]
Education Ph.D. The Ohio State University
M.Sc. The Ohio State University
Research Interests HonDip. Hong Kong Baptist University
Thin Film Technology, Raman Spectroscopy & Spectroscopic
ORCiD Ellipsometry, Optical Characterization
Publication 0000-0002-2992-7884
H-index 132
Sum of the Times Cited 25
2387

Awards Publications (selected)

•• Faculty Award for Outstanding Performance/ •• “High-performance fiber-shape supercapacitors using
Achievement in Teaching 2014/15 (Team Award), PolyU carbon fiber thread (CFT)@polyanilne and functionalized
CFT electrodes for wearable/ stretchable electronics”,
•• President’s Award for Excellent Performance/ Jin, HY; Zhou, LM, Mak, CL; et al., Nano Energy 11, 662
Achievement in Community Service 2010/2011 (Team (2015).
Award), PolyU
•• “Facile hydrothermal synthesis of hydrotropic Cu2ZnSnS4
•• 中國分析測試協會科學技術獎 (CAIA 獎 ) 一等獎 (2002) nanocrystal quantum dots: band-gap engineering and
phonon confinement effect”, Liu, WC; Gu, BL; Wu, XS;
Professional Activity Mak, CL., J. Mater. Chem. A 1, 3182 (2013).

•• Council member, Physical Society of Hong Kong (2008- •• “Thermo-optic properties of epitaxial Sr0.6Ba0.4Nb2O6
2014) waveguides and their application as optical modulator”
Liu, WC; Mak, CL, Wong KH, Optics Express 17, 13677
Community Services (2009).

•• Member, Textbook Committee, Physics Textbook Review •• “Self-cleaning cotton”, Qi, KH; Daoud, WA, Xin, JH;
Panel (Secondary), Education & Manpower Bureau Mak, CL, J. Mater. Chem. 16, 4567 (2006).
(2013-present)
•• “High tunability in compositionally graded epitaxial barium
•• Member, HKCE Physics Subject Committee, Hong Kong strontium titanate thin films by pulsed-laser deposition”,
Examinations & Assessment Authority (2008-2011) Lu, SG; Zhu, XH; Mak, CL; et al., Appl. Phys. Letts 82,
2877 (2003).

196 Research at FAST

Research Overview

Ferroelectric Ceramics, Thin Films and Composites

Rare-Earth-doped BFO ceramics, (K0.5 Na0.5)2x(Sr0.6Ba0.4)5-xNb10O30 (KNSBN) ceramics with ‘unfilled’ and ‘filled’ tetragonal tung-
sten-bronze structure, SBN & SCNN thin films and nanocrystals, Ca-dopant (Sr0.6Ba0.4)4Na2Nb10O30 ceramics, fine grain mag-
netoelectric PZT-NZFO composites.
• Structural, pyroelectric, ferroelectric, magnetic and dielectric properties measurments
• Optical characterization (Raman, photoluminescence, ellipsometry)
• Impedance spectroscopy
• Phase transition (dielectric properties, temperature dependent micro-Raman)

The transmittance, bandgap, polarization and magnetization of different ferroelectric materials

Cu2ZnSnS4 (CZTS) Based Solar Cell (CIGS)) family,

• Compared to I-III-VI2 (CuIn1-xGaxSe2
cheaper, nontoxic

• Has a near-optimum direct band gap energy of ~1.5 eV and a
large absorption coefficient (>104 cm-1).

• Theoretical limit for CZTS is 32.2%

Department of Applied Physics

Metallization of Fabrics

• Metallization of flexible nonconducting substrates : cotton &
polymer fabrics

• Wearable electronics

Conducting PET fabrics Supercapacitor developed from PET

The Hong Kong Polytechnic University 197

Our Researchers

Department of Applied Physics

Dr MANTE Pierre Adrien

Assistant Professor

Phone Number (852) 2766 5883
Email [email protected]
Education Postdoc Lund University
Postdoc National Taiwan University
Research Interests Ph.D. Lille University of Science and Technology
ORCiD M.Sc. Henri Poincare University
Publication National School of Mines
H-index Ultrafast phenomena, Coherent phonons, Nonlinear optics
Sum of the Times Cited 0000-0002-4950-5152
28
10
204

Awards and Honours Publications (selected)

•• Young Investigator grant from Swedish Research •• P.-A. Mante (Corresponding), C. Stoumpos, M. Ka-
Council (as PI, HK$ 4M) 2017 natzidis, A. Yartsev, “High Charge Mobility Limit in CH3N-
H3PbI3 Revealed by Coherent Acoustic Phonons”, Na-
•• NanoLund (Sweden) Junior Scientist Grant (as PI, ture Commun. 8, 14398 (2017).
HK$ 100k) 2017
•• P.-A. Mante (Corresponding), S. Lehmann, N. Anttu,
•• Crafoord (Sweden) Research Grant (as co-I, HK$ K. A. Dick, A. Yartsev, “Non-destructive Com-
300k) 2016 plete Mechanical Characterization of Zinc Blende and
Wurtzite GaAs Nanowires using Time-Resolved
•• NanoLund (Sweden) Grant (as co-I, HK$ 400k) 2015 Pump-Probe Spectroscopy”, Nano Lett. 16, 4792
(2016).
•• National Science Council (Taiwan) – Best paper
award 2014 •• P.-A. Mante, Y.-R. Huang, S.-C. Yang, T.-M. Liu, A. A.
Maznev, J.-K. Sheu, C.-K. Sun, “THz acoustic phonon
•• IEEE IUS 2008 - Best student award spectroscopy and nanoscopy by using piezoelectric
semiconductor heterostructures”, Ultrasonics 56, 52
Book Chapter (2015) (Invited Review).

•• P.-A. Mante, C.-C. Chen, Y.-R. Huang, J.-K. Sheu, C.- •• I.-J. Chen, P.-A. Mante, C.-K. Chang, S.-C. Yang, H.-
K. Sun, “Real Time Imaging of Chemical Reaction with Y. Chen, Y.-R. Huang , K.-H. Chen, V. Gusev, C.-K. Sun,
a Subnanometer Resolution by Using Nanoultrason- “Energy Transfer Channel through Longitudinal Acoustic
ics”, in Acoustic Imaging, Volume 32, pp. 131-140, W. Phonon in Supported Monolayer Graphene”, Nano
S. Gan Ed., Research Publishing, Singapore (2015). Lett. 14, 1317 (2014).
ISBN-13:978-981-09-2691-5. ISBN-10:981-09-2691-X.
•• P.-A. Mante, C.-C. Chen, Y.-C. Wen, J.-K. Sheu, C.-K.
Sun, “Thermal Boundary Resistance between GaN and
Cubic ice and THz Acoustic Attenuation of Cubic Ice
from Complex Acoustic Impedance Measurements”,
Phys. Rev. Lett. 111, 225901 (2013).

•• P.-A. Mante, Y.-C. Wu, C.-Y. Ho, L.-W. Tu, C.-K. Sun, “Gi-
gahertz Coherent Guided Acoustic Phonons in AlN/GaN
Nanowire Superlattice”, Nano Lett. 13, 1139 (2013).

198 Research at FAST


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