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中国科学院大学学报 ›› 2010, Vol. 27 ›› Issue (5): 590-598.DOI: 10.7523/j.issn.2095-6134.2010.5.003

• 论文 • 上一篇    下一篇

基于弱测量的量子系统消相干控制

楼越升, 丛爽   

  1. 中国科学技术大学自动化系, 合肥 230027
  • 收稿日期:2009-09-15 修回日期:2010-04-19 发布日期:2010-09-15
  • 通讯作者: 丛爽
  • 基金资助:

    Supported by the National Natural Science Foundation of China (60774098), the National Key Basic Research Program (2006CB922004), and the USTC Initiative Foundation (KD2007045) 

Weak measurement-based decoherence control of quantum systems

LOU Yue-Sheng, CONG Shuang   

  1. Department of Automation, University of Science and Technology of China, Hefei 230027,China
  • Received:2009-09-15 Revised:2010-04-19 Published:2010-09-15
  • Supported by:

    Supported by the National Natural Science Foundation of China (60774098), the National Key Basic Research Program (2006CB922004), and the USTC Initiative Foundation (KD2007045) 

摘要:

研究了弱测量的性质以及潜在应用.首先,针对所定义的一类特定的正定算子值测量,从线性赋范空间的角度推导出其为弱测量时的参数条件.其次,讨论了弱测量的适用性:弱测量不仅适用于大量全同量子系统,若任意的测量算符都能够被选择性地施加,则弱测量也能够对单个的量子系统进行测量.最后,考察了弱测量对不同的量子系统的影响:对于大量全同量子系统,连续的弱测量对状态产生的影响相当于一个消相位过程,而对于单个的二能级量子系统,弱测量能够被用来抑制消相位以及去极化过程.

关键词: 量子系统控制, 弱测量, 状态演化, 消相干控制

Abstract:

Properties and potential applications of weak measurement are investigated. First, a kind of positive operator-valued measurement is defined, and a sufficient condition is deduced for weak measurement from the view of linear normed space. Secondly, the applicability of weak measurement is discussed. It is shown that weak measurement is applicable not only to a set of identical quantum systems, but also to a single quantum system if any measurement operator can be selectively implemented. Finally, the effects of weak measurement on different quantum systems are studied. For a set of identical quantum systems, weak measurement affects states as a dephasing process. However, for a two-level single quantum system, it can be used to inhibit dephasing and to depolarization processes.

Key words: quantum system control, weak measurement, states evolvement, decoherence control

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