Lüschen Henrik P, Bordia Pranjal, Scherg Sebastian, Alet Fabien, Altman Ehud, Schneider Ulrich, Bloch Immanuel
Fakultät für Physik, Ludwig-Maximilians-Universität München, Schellingstr. 4, 80799 Munich, Germany.
Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching, Germany.
Phys Rev Lett. 2017 Dec 29;119(26):260401. doi: 10.1103/PhysRevLett.119.260401. Epub 2017 Dec 27.
In the presence of sufficiently strong disorder or quasiperiodic fields, an interacting many-body system can fail to thermalize and become many-body localized. The associated transition is of particular interest, since it occurs not only in the ground state but over an extended range of energy densities. So far, theoretical studies of the transition have focused mainly on the case of true-random disorder. In this work, we experimentally and numerically investigate the regime close to the many-body localization transition in quasiperiodic systems. We find slow relaxation of the density imbalance close to the transition, strikingly similar to the behavior near the transition in true-random systems. This dynamics is found to continuously slow down upon approaching the transition and allows for an estimate of the transition point. We discuss possible microscopic origins of these slow dynamics.
在存在足够强的无序或准周期场的情况下,相互作用的多体系统可能无法热化并进入多体局域化状态。相关的转变特别令人感兴趣,因为它不仅发生在基态,而且在能量密度的扩展范围内都会出现。到目前为止,对该转变的理论研究主要集中在真正随机无序的情况。在这项工作中,我们通过实验和数值方法研究了准周期系统中接近多体局域化转变的区域。我们发现在接近转变时密度失衡的弛豫很慢,这与真正随机系统中接近转变时的行为惊人地相似。这种动力学在接近转变时会持续减慢,并能据此估计转变点。我们讨论了这些缓慢动力学可能的微观起源。