Can we observe the many-body localization?
Can we observe the many-body localization?
复制标题
我们能观察到多体定位吗？
DOI：
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
J. Zakrzewski
中科院分区：
文献类型：
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作者：
P. Sierant;J. Zakrzewski
本文研究了一维无序海森堡自旋-1/2链的时间动力学，重点研究了一个大系统尺寸和长时间演化的体系。这一机制与多体局部化（MBL）的观测有关，多体局部化是一种冻结系统动力学并阻止其达到热平衡的现象。我们对MBL的实验研究中经常使用的不平衡进行了广泛的数值模拟，结果表明，不平衡的缓慢幂律衰减持续到无序强度至少超过当前MBL临界无序强度估计的2倍。即使我们研究了几千次隧道的时间演变，我们也没有观察到不平衡饱和的迹象，这表明系统动力学冻结，并提供了MBL的确凿证据。我们证明，当无序被准周期势取代时，情况在性质上是不同的。在这种情况下，我们观察到不平衡振荡模式的出现，该模式相对于系统大小的变化是稳定的。这表明，只要准周期势足够强，准周期系统的动力学在我们所达到的最长时间尺度上仍然是完全局部的。我们的研究在MBL现象的明确实验观察中发现了挑战。
We study time dynamics of 1D disordered Heisenberg spin-1/2 chain focusing on a regime of large system sizes and a long time evolution. This regime is relevant for observation of manybody localization (MBL), a phenomenon that is expected to freeze the dynamics of the system and prevent it from reaching thermal equilibrium. Performing extensive numerical simulations of the imbalance, a quantity often employed in the experimental studies of MBL, we show that the regime of a slow power-law decay of imbalance persists to disorder strengths exceeding by at least a factor of 2 the current estimates of the critical disorder strength for MBL. Even though we investigate time evolution up to few thousands tunneling times, we observe no signs of the saturation of imbalance that would suggest freezing of system dynamics and provide a smoking gun evidence of MBL. We demonstrate that the situation is qualitatively different when the disorder is replaced by a quasiperiodic potential. In this case, we observe an emergence of a pattern of oscillations of the imbalance that is stable with respect to changes in the system size. This suggests that the dynamics of quasiperiodic systems remain fully local at the longest time scales we reach provided that the quasiperiodic potential is sufficiently strong. Our study identifies challenges in an unequivocal experimental observation of the phenomenon of MBL.
影响因子：
64.8
作者：
通讯作者：
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影响因子：
19.6
作者：
Léonard, Julian;Kim, Sooshin;Rispoli, Matthew;Lukin, Alexander;Schittko, Robert;Kwan, Joyce;Demler, Eugene;Sels, Dries;Greiner, Markus
通讯作者：
Greiner, Markus