Observation of Stark many-body localization without disorder.
Observation of Stark many-body localization without disorder.
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DOI：
10.1038/s41586-021-03988-0
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发表时间：
2021-11
期刊：
影响因子：
64.8
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中科院分区：
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热化是统计物理中一个普遍存在的过程，在这个过程中，少体观测的细节被洗掉，而有利于一个无特征的稳态。即使在孤立的量子多体系统中，限于可逆动力学，热化通常也占上风。然而，在这些系统中，还有另一种可能性：多体局域化（MBL）可以导致非热状态的保存。虽然长期以来，无序一直被认为是这种现象的重要组成部分，但最近的理论工作表明，具有均匀增加的场的量子多体系统-但没有无序-也可以表现出MBL，导致“斯塔克MBL”。在这里，我们实现斯塔克MBL在捕获离子量子模拟器，并证明其关键属性：停止热化和缓慢传播的相关性。定制的离子自旋之间的相互作用在一个有效的场梯度，我们直接观察到它们的微观平衡的各种初始状态，我们应用单点控制来测量自旋链的不同区域之间的相关性。此外，通过设计一个变化的梯度，我们创建了一个无无序系统与共存的长寿命热化和非热区域。结果表明，MBL意想不到的一般性，与热化的基本要求和工程长寿命的非平衡量子物质的潜在用途的影响。
Thermalization is a ubiquitous process of statistical physics, in which details of few-body observables are washed out in favor of a featureless steady state. Even in isolated quantum many-body systems, limited to reversible dynamics, thermalization typically prevails. However, in these systems, there is another possibility: many-body localization (MBL) can result in preservation of a non-thermal state. While disorder has long been considered an essential ingredient for this phenomenon, recent theoretical work has suggested that a quantum many-body system with a uniformly increasing field—but no disorder—can also exhibit MBL, resulting in ‘Stark MBL’. Here we realize Stark MBL in a trapped-ion quantum simulator and demonstrate its key properties: halting of thermalization and slow propagation of correlations. Tailoring the interactions between ionic spins in an effective field gradient, we directly observe their microscopic equilibration for a variety of initial states, and we apply single-site control to measure correlations between separate regions of the spin chain. Further, by engineering a varying gradient, we create a disorder-free system with coexisting long-lived thermalized and nonthermal regions. The results demonstrate the unexpected generality of MBL, with implications about the fundamental requirements for thermalization and with potential uses in engineering long-lived non-equilibrium quantum matter.