Wu Ling-Na, Eckardt André
Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, D-01187 Dresden, Germany.
Phys Rev Lett. 2019 Jul 19;123(3):030602. doi: 10.1103/PhysRevLett.123.030602.
We investigate the relaxation dynamics of an interacting Stark-localized system coupled to a dephasing bath, and compare its behavior to the conventional disorder-induced many body localized system. Specifically, we study the dynamics of population imbalance between even and odd sites, and the growth of the von Neumann entropy. For a large potential gradient, the imbalance is found to decay on a timescale τ that grows quadratically with the Wannier-Stark tilt. For the noninteracting system, it shows an exponential decay, which becomes a stretched exponential decay in the presence of finite interactions. This is different from a system with disorder-induced localization, where the imbalance exhibits a stretched exponential decay also for vanishing interactions. As another clear qualitative difference, we do not find a logarithmically slow growth of the von Neumann entropy as it is found for the disordered system. Our findings can immediately be tested experimentally with ultracold atoms in optical lattices.
我们研究了与退相干浴耦合的相互作用斯塔克局域化系统的弛豫动力学，并将其行为与传统的无序诱导多体局域化系统进行比较。具体而言，我们研究了偶数和奇数格点之间的粒子数不平衡动力学以及冯·诺依曼熵的增长。对于较大的势梯度，发现不平衡在时间尺度τ上衰减，τ随万尼尔 - 斯塔克倾斜度呈二次方增长。对于非相互作用系统，它呈现指数衰减，在存在有限相互作用时变为拉伸指数衰减。这与无序诱导局域化系统不同，在无序诱导局域化系统中，即使相互作用消失，不平衡也呈现拉伸指数衰减。作为另一个明显的定性差异，我们没有发现冯·诺依曼熵像在无序系统中那样呈对数缓慢增长。我们的发现可以立即通过光学晶格中的超冷原子进行实验验证。
