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arXiv 1402.3299cond-mat.stat-mech
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相互作用量子系统弛豫动力学的一般特征

General Features of the Relaxation Dynamics of Interacting Quantum Systems

E. J. Torres-Herrera, Manan Vyas, Lea F. Santos

摘要:

我们通过数值和解析方法研究瞬时脱离平衡(猝灭)的孤立相互作用量子系统。在时间上找到初始状态的概率,即所谓的保真度,在由完全随机矩阵描述的系统中衰减最快,其中同时存在多体相互作用。在具有两体相互作用的现实系统中,动力学较慢,并且取决于初始状态和表征系统的哈密顿量之间的相互作用。在这种情况下,最快的保真度衰减是高斯衰减,并且可以持续到饱和。一个简单的一般图片,其中保真度起着核心作用,也实现了短时间动力学的少体观测。它适用于作为观测量的本征态的初始状态。我们还讨论了需要重新评估的分析表达式,以前提出来描述的香农熵的演变。我们的分析主要是针对光晶格中冷原子实验中可以制备的初始态。

英文摘要:

We study numerically and analytically isolated interacting quantum systems that are taken out of equilibrium instantaneously (quenched). The probability of finding the initial state in time, the so-called fidelity, decays fastest for systems described by full random matrices, where simultaneous many-body interactions are implied. In the realm of realistic systems with two-body interactions, the dynamics is slower and depends on the interplay between the initial state and the Hamiltonian characterizing the system. The fastest fidelity decay in this case is Gaussian and can persist until saturation. A simple general picture, in which the fidelity plays a central role, is also achieved for the short-time dynamics of few-body observables. It holds for initial states that are eigenstates of the observables. We also discuss the need to reassess analytical expressions that were previously proposed to describe the evolution of the Shannon entropy. Our analyses are mainly developed for initial states that can be prepared in experiments with cold atoms in optical lattices.

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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