标题： 孤立量子系统的新的平衡系综 显示英文标题

标题： New equilibrium ensembles for isolated quantum systems

摘要： 孤立量子系统的幺正动力学不允许纯态热化。 由于这个原因，如果一个孤立量子系统达到平衡，它将根据所谓的“对角系综”$\rho_{DE}$的预测进行。 基于Jaynes最大熵原理提供的直觉，本文我们提出一种新方法，以生成对$\rho_{DE}$的逐步改进的近似。 作为例子，我们写出一组分层的系综，这些系综可以用来描述小孤立量子系统的平衡物理，超越Gibbs系综的“热假设”。 显示英文摘要

摘要： The unitary dynamics of isolated quantum systems does not allow a pure state to thermalize. Because of that, if an isolated quantum system equilibrates, it will do so to the predictions of the so-called "diagonal ensemble" $\rho_{DE}$. Building on the intuition provided by Jaynes' maximum entropy principle, in this paper we present a novel technique to generate progressively better approximations to $\rho_{DE}$. As an example, we write down a hierarchical set of ensembles which can be used to describe the equilibrium physics of small isolated quantum systems, going beyond the "thermal ansatz" of Gibbs ensembles.