Experimental observation of a generalized Gibbs ensemble
Experimental observation of a generalized Gibbs ensemble
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DOI：
10.1126/science.1257026
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发表时间：
2015-04-10
期刊：
影响因子：
56.9
通讯作者：
Schmiedmayer, Joerg
中科院分区：
文献类型：
--
作者：
Langen, Tim;Erne, Sebastian;Schmiedmayer, Joerg
在统计力学框架下描述孤立量子多体系统的非平衡动力学是一个基本的开放问题。传统的热力学系综不能描述表现出非平凡守恒量的大类系统，而广义系综则被预测在这些系统中实现最大的熵。实验表明，简并的一维玻色气体弛豫到可以用这种广义系综来描述的状态。通过对高达10阶的相关函数的详细研究，证实了这一点。广义系综描述对孤立量子多体系统的适用性表明，经典统计性质是从微观么正量子演化中自然出现的。
The description of the non-equilibrium dynamics of isolated quantum many-body systems within the framework of statistical mechanics is a fundamental open question. Conventional thermodynamical ensembles fail to describe the large class of systems that exhibit nontrivial conserved quantities, and generalized ensembles have been predicted to maximize entropy in these systems. We show experimentally that a degenerate one-dimensional Bose gas relaxes to a state that can be described by such a generalized ensemble. This is verified through a detailed study of correlation functions up to 10th order. The applicability of the generalized ensemble description for isolated quantum many-body systems points to a natural emergence of classical statistical properties from the microscopic unitary quantum evolution.