校园动态
香港理工大学张国锋教授来校做学术报告
发布时间:2019-03-01 09:38:19 6857

2019年2月27日上午,应机电工程与自动化学院吴爱国教授邀请,香港理工大学应用数学系博士生导师张国锋教授来我校举办了学术讲学。张国峰教授的主攻方向是量子信息和控制,数据采样控制及非线性系统等。

张国峰教授于2月27日上午10:30在A栋509作了题为“Structural Decomposition for Quantum Linear Systems”的学术报告。报告由吴爱国教授主持,张颖副教授以及对该方向感兴趣的博士、硕士研究生参加了报告会。

报告中,张国峰教授将此次讲座内容分成三部分,分别介绍了量子系统的发展、当前的研究工作以及未来的研究方向等。第一部分中,系统阐述了量子系统的演化过程与数学描述方程。并且说明薛定谔方程是量子方程的一种特例。第二部分中,通过大量的实例说明量子系统的普遍存在性,并且具有重要的研究意义。例如,分束器系统、光枪系统和简化的参数放大器系统等。同时,详细介绍了线性量子系统的卡尔曼分解问题。这部分从控制论的角度,介绍量子线性系统的能控性、能观性与Hurwitz稳定性之间的等价关系。第三部分中,张国峰教授指出未来关于量子系统的研究工作将扩展到非线性系统中,是一个难度较大的课题。会后,张国锋教授和与会师生进行了现场互动交流,并对同学们提出的问题给予了细致耐心的解答。 通过此次张国峰教授的讲座,参加报告的师生纷纷表示受益匪浅。

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Speaker: Guofeng Zhang

Department of Applied Mathematics, The Hong Kong Polytechnic University

 

Email: guofeng.zhang@polyu.edu.hk

Structural Decomposition for Quantum Linear Systems

Abstract:

In this talk we study the structure of quantum linear systems in terms of their Kalman canonical form. Physical realizability conditions for the  Kalman canonical form are given, which shed light on various relations among the components of the system matrices for the Kalman canonical form. These relations are used to explore the structure of the spectrum  of quantum linear systems. The spectral structure obtained indicates that a quantum linear system is both controllable and observable if it is Hurwitz stable.  A new parameterization method for quantum linear systems is proposed. This new parameterization is designed for the Kalman canonical form directly. Consequently, the parameters involved are in a blockwise form in correspondence with the blockwise structure of the Kalman canonical form. This parameter structure can be used to simplify various quantum control design problems. For example,  necessary and sufficient conditions for the realization of back-action evading (BAE) measurements  are given in terms of these new parameters that specify the Kalman canonical form. Due to their blockwise nature, a small number of parameters are required for realizing BAE measurements. Moreover, it is shown that a refined structure of these physical parameters reveals the noiseless subsystem and invariant subsystems of a given quantum linear system.

  

 Prof. Guofeng Zhang received his B.Sc. degree and M.Sc. degree from Northeastern University, Shenyang, China, in 1998 and 2000 respectively. He received a Ph.D. degree in Applied Mathematics from the University of Alberta, Edmonton, Canada, in 2005. During 2005–2006, he was a Postdoc Fellow at the University of Windsor, Windsor, Canada. He joined the School of Electronic Engineering of the University of Electronic Science and Technology of China, Chengdu, China, in 2007. From April 2010 to December 2011 he was a Research Fellow at the Australian National University. He is currently an Associate Professor in the Department of Applied Mathematics at the Hong Kong polytechnic University. His research interests include quantum information and control, sampled-data control and nonlinear dynamics.