Towards laser control of open quantum systems: memory effects
Towards laser control of open quantum systems: memory effects
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DOI：
10.1080/00268976.2017.1319085
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发表时间：
2016-11
影响因子：
1.7
通讯作者：
R. Puthumpally-Joseph;O. Atabek;E. Mangaud;M. Desouter-Lecomte;D. Sugny
中科院分区：
文献类型：
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作者：
R. Puthumpally-Joseph;O. Atabek;E. Mangaud;M. Desouter-Lecomte;D. Sugny
摘要与孤立的小尺寸分子相比，开放量子系统（OQS）的激光控制是一个具有挑战性的问题，主要是由于要考虑非常大的自由度。这样的控制旨在适当地优化中心两能级系统（例如，给定的振动模式）朝向其环境浴（包括例如所有其他正常模式）的退相干过程。可以设想各种应用，以保护中央系统免于衰变（长时间分子排列或取向，量子位退相干保护），或者加速朝向浴的信息流（长链有机化合物中的有效电荷或质子转移）。实现这样的控制需要一些定量措施的退相干与记忆效应的浴响应，实际上是由非马尔可夫的程度。利用Nakajima-Zwanzig型主方程计算了自旋玻色子模型的特征退相干率，并将其与记忆核的运动展开方程进行了融合。它示出，通过适当地调谐的两个能级跃迁频率，通过由外部激光场产生的受控斯塔克位移，非马尔可夫性可以在一个连续的方式得到增强，导致第一次尝试朝向控制OQS。
ABSTRACT Laser control of open quantum systems (OQS) is a challenging issue as compared to its counterpart in isolated small size molecules, basically due to very large numbers of degrees of freedom to be accounted for. Such a control aims at appropriately optimising decoherence processes of a central two-level system (a given vibrational mode, for instance) towards its environmental bath (including, for instance, all other normal modes). A variety of applications could potentially be envisioned, either to preserve the central system from decaying (long duration molecular alignment or orientation, qubit decoherence protection) or, to speed up the information flow towards the bath (efficient charge or proton transfers in long chain organic compounds). Achieving such controls requires some quantitative measures of decoherence in relation with memory effects in the bath response, actually given by the degree of non-Markovianity. Characteristic decoherence rates of a Spin-Boson model are calculated using a Nakajima–Zwanzig type master equation with converged hierarchical equations of motion expansion for the memory kernel. It is shown that, by adequately tuning the two-level transition frequency through a controlled Stark shift produced by an external laser field, non-Markovianity can be enhanced in a continuous way leading to a first attempt towards the control of OQS.