标题： 沿单个核轨迹的电子退相干 显示英文标题

标题： Electronic decoherence along a single nuclear trajectory

摘要： 我们描述了一种新的子系统退相干方法，无需通常的环境追踪操作。关注的子系统完全由一个沿其环境单个经典轨迹非幺正演化的纯态描述。该方法是从电子和原子核任意系统的精确分解框架推导出来的。电子动力学的非幺正性仅来自于电子和原子核之间的非绝热关联。我们证明，该方法正确描述了核轨迹通过避免交叉时的相干性增益和随后的退相干，这是单轨迹埃伦费斯特动力学无法产生退相干的典型情况。我们进一步证明，幺正和非幺正电子动力学之间的本质区别体现在表征短时间区域的时间常数中。 显示英文摘要

摘要： We describe a novel approach to subsystem decoherence without the usual tracing-out of the environment. The subsystem of focus is described entirely by a pure state evolving non-unitarily along a single classical trajectory of its environment. The approach is deduced from the exact factorization framework for arbitrary systems of electrons and nuclei. The non-unitarity of the electronic dynamics arises exclusively from non-adiabatic correlations between electrons and nuclei. We demonstrate that the approach correctly describes the coherence gain and the subsequent decoherence for the example of a nuclear trajectory passing through an avoided crossing, the prototypical case where single-trajectory Ehrenfest dynamics fails to produce decoherence. We further demonstrate that the essential difference between unitary and non-unitary electronic dynamics shows up in the time constants characterising the short-time regime.