中国物理B ›› 2018, Vol. 27 ›› Issue (6): 60302-060302.doi: 10.1088/1674-1056/27/6/060302

• GENERAL • 上一篇    下一篇

Quantum speed-up capacity in different types of quantum channels for two-qubit open systems

Wei Wu(吴薇), Xin Liu(刘辛), Chao Wang(王超)   

  1. 1 Department of Physics, School of Science, Wuhan University of Technology(WUT), Wuhan 430070, China;
    2 School of Engineering and Digital Arts, University of Kent, Canterbury, United Kingdom
  • 收稿日期:2017-11-16 修回日期:2018-02-19 出版日期:2018-06-05 发布日期:2018-06-05
  • 通讯作者: Xin Liu E-mail:lxheroes@126.com
  • 作者简介:Wei Wu,E-mail:14171929@qq.com;Chao Wang,E-mail:C.Wang@kent.ac.uk
  • 基金资助:
    Project supported by the EU FP7 Marie-Curie Career Integration Fund (Grant No.631883)(for Chao Wang),the Royal Society Research Fund (Grant No.RG150036),and the Fundamental Research Fund for the Central Universities,China (Grant No.2018IB010)(for Xin Liu and Wei Wu).

Quantum speed-up capacity in different types of quantum channels for two-qubit open systems

Wei Wu(吴薇)1, Xin Liu(刘辛)1, Chao Wang(王超)2   

  1. 1 Department of Physics, School of Science, Wuhan University of Technology(WUT), Wuhan 430070, China;
    2 School of Engineering and Digital Arts, University of Kent, Canterbury, United Kingdom
  • Received:2017-11-16 Revised:2018-02-19 Online:2018-06-05 Published:2018-06-05
  • Contact: Xin Liu E-mail:lxheroes@126.com
  • Supported by:
    Project supported by the EU FP7 Marie-Curie Career Integration Fund (Grant No.631883)(for Chao Wang),the Royal Society Research Fund (Grant No.RG150036),and the Fundamental Research Fund for the Central Universities,China (Grant No.2018IB010)(for Xin Liu and Wei Wu).

摘要: A potential acceleration of a quantum open system is of fundamental interest in quantum computation, quantum communication, and quantum metrology. In this paper, we investigate the “quantum speed-up capacity” which reveals the potential ability of a quantum system to be accelerated. We explore the evolutions of the speed-up capacity in different quantum channels for two-qubit states. We find that although the dynamics of the capacity is varying in different kinds of channels, it is positive in most situations which are considered in the context except one case in the amplitude-damping channel. We give the reasons for the different features of the dynamics. Anyway, the speed-up capacity can be improved by the memory effect. We find two ways which may be used to control the capacity in an experiment:selecting an appropriate coefficient of an initial state or changing the memory degree of environments.

关键词: quantum speed-up capacity, quantum speed limit, two-qubit open systems, quantum channel, memory effect

Abstract: A potential acceleration of a quantum open system is of fundamental interest in quantum computation, quantum communication, and quantum metrology. In this paper, we investigate the “quantum speed-up capacity” which reveals the potential ability of a quantum system to be accelerated. We explore the evolutions of the speed-up capacity in different quantum channels for two-qubit states. We find that although the dynamics of the capacity is varying in different kinds of channels, it is positive in most situations which are considered in the context except one case in the amplitude-damping channel. We give the reasons for the different features of the dynamics. Anyway, the speed-up capacity can be improved by the memory effect. We find two ways which may be used to control the capacity in an experiment:selecting an appropriate coefficient of an initial state or changing the memory degree of environments.

Key words: quantum speed-up capacity, quantum speed limit, two-qubit open systems, quantum channel, memory effect

中图分类号:  (Decoherence; open systems; quantum statistical methods)

  • 03.65.Yz
03.65.Ta (Foundations of quantum mechanics; measurement theory) 03.67.Mn (Entanglement measures, witnesses, and other characterizations)