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arXiv 1407.7154quant-phcond-mat.stat-mech
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弱测量下的Landau-Zener演化:在非绝热和绝热测量协议下Zeno效应的表现

Landau-Zener evolution under weak measurement: Manifestation of the Zeno effect under diabatic and adiabatic measurement protocols

Anna Novelli, Wolfgang Belzig, Abraham Nitzan

摘要:

分析了连续弱非选择性测量下Landau-Zener-Stueckelberg-Majorana(LZ)过程的时间演化和渐近结果.我们比较两个测量协议,其中无论是绝热或非绝热水平的人口(连续和弱)监测。弱测量形式主义,使用高斯克劳斯算子描述,导致时间演化的特点是马尔可夫失相过程,这在非绝热测量协议是类似于早期的研究LZ动态在失相环境。铸造的语言的测量理论的问题,使我们有可能比较非绝热和绝热测量方案,考虑工程失相作为控制设备,并检查芝诺效应的表现在不同的测量协议。特别地,在非绝热布居的测量下,芝诺效应不是表现为被测系统在其初始状态下的冻结,而是表现为两个非绝热状态的相等渐近布居的方法。这种行为可以追溯到弱测量形式主义在强测量极限中的行为方式,测量时间和强度之间存在内在关系。

英文摘要:

The time evolution and the asymptotic outcome of a Landau-Zener-Stueckelberg-Majorana (LZ) process under continuous weak non-selective measurement is analyzed. We compare two measurement protocols in which the populations of either the adiabatic or the non-adiabatic levels are (continuously and weakly) monitored. The weak measurement formalism, described using a Gaussian Kraus operator, leads to a time evolution characterized by a Markovian dephasing process, which, in the non-adiabatic measurement protocol is similar to earlier studies of LZ dynamics in a dephasing environment. Casting the problem in the language of measurement theory makes it possible for us to compare diabatic and adiabatic measurement scenarios, to consider engineered dephasing as a control device and to examine the manifestation of the Zeno effect under the different measurement protocols. In particular, under measurement of the non- adiabatic populations, the Zeno effect is manifested not as a freezing of the measured system in its initial state, but rather as an approach to equal asymptotic populations of the two diabatic states. This behavior can be traced to the way by which the weak measurement formalism behaves in the strong measurement limit, with a built-in relationship between measurement time and strength.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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