Time evolution of many-body localized systems in two spatial dimensions
Time evolution of many-body localized systems in two spatial dimensions
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DOI：
10.1103/physrevb.102.235132
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发表时间：
2019-10
影响因子：
3.7
通讯作者：
A. Kshetrimayum;M. Goihl;J. Eisert
中科院分区：
文献类型：
--
作者：
A. Kshetrimayum;M. Goihl;J. Eisert
多体局域化是防止相互作用量子系统热化的一种引人注目的机制。例如，缺乏热化行为本身就表现在局部粒子数组态的剩余量上，这个量在参数范围内是稳健的--不同于其他可积性的情况。在最先进的量子模拟器中，甚至在两个空间维度的冷原子系统中，局部粒子数都可以直接获取。然而，对此类量子模拟器进行基准测试的经典模拟极具挑战性。在这项工作中，我们提出了一个全面的张量网络模拟的多体局域系统在空间维度使用一种变种的iPEPS算法。通过将无序实现到辅助自旋系统中，可以恢复所需的平移不变性，从而在动力学下提供精确的无序平均。我们观察到无限大系统的多体局部化特征。有趣的是，在这种有限多无序值的设置下，局域化出现在相互作用机制中，我们为此提供了一个直观的论点，而安德森局域化是缺席的。我们将我们的结果与涉及非相互作用费米子的模拟进行基准比较，发现结果与局域化的缺失是兼容的。
Many-body localization is a striking mechanism that prevents interacting quantum systems from thermalizing. The absence of thermalization behaviour manifests itself, for example, in a remanence of local particle number configurations, a quantity that is robust over a parameter range -- unlike the situation in other instances of integrability. Local particle numbers are directly accessible in state-of-the-art quantum simulators, in systems of cold atoms even in two spatial dimensions. Yet, the classical simulation to benchmark such quantum simulators is highly challenging. In this work, we present a comprehensive tensor network simulation of a many-body localized systems in spatial dimensions using a variant of an iPEPS algorithm. The required translational invariance can be restored by implementing the disorder into an auxiliary spin system, providing an exact disorder average under dynamics. We observe signatures of many-body localization for the infinite system. Interestingly, in this setting of finitely many disorder values, localization emerges in the interacting regime, for which we provide an intuitive argument, while Anderson localization is absent. We benchmark our results against a simulation involving non-interacting fermions and find results compatible with an absence of localization.