Eigenstate Thermalization in a Locally Perturbed Integrable System
Eigenstate Thermalization in a Locally Perturbed Integrable System
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DOI：
10.1103/physrevlett.125.070605
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发表时间：
2020-08-13
影响因子：
8.6
通讯作者：
Rigol, Marcos
中科院分区：
文献类型：
--
作者：
Brenes, Marlon;LeBlond, Tyler;Rigol, Marcos
本征态热化被广泛认为是一般孤立量子系统热化的机制。以自旋为1/2的可积XXZ链中的单个磁缺陷为例，我们证明了对可积系统进行局部扰动可以引起本征态热化。这种设置的独特之处在于，未扰动可积链的热力学和输运性质出现在扰动（不可积）链的本征态性质中。具体地说，我们表明，在扰动本征态中的观察量的对角矩阵元素遵循微正则预测的可积模型，和弹道字符的自旋输运在可积模型中的表现在行为的非对角矩阵元素的当前运营商在扰动本征态。
Eigenstate thermalization is widely accepted as the mechanism behind thermalization in generic isolated quantum systems. Using the example of a single magnetic defect embedded in the integrable spin-1/2 XXZ chain, we show that locally perturbing an integrable system can give rise to eigenstate thermalization. Unique to such setups is the fact that thermodynamic and transport properties of the unperturbed integrable chain emerge in properties of the eigenstates of the perturbed (nonintegrable) one. Specifically, we show that the diagonal matrix elements of observables in the perturbed eigenstates follow the microcanonical predictions for the integrable model, and that the ballistic character of spin transport in the integrable model is manifest in the behavior of the off-diagonal matrix elements of the current operator in the perturbed eigenstates.