Yao N Y, Laumann C R, Cirac J I, Lukin M D, Moore J E
Department of Physics, University of California, Berkeley, California 94720, USA.
Department of Physics, University of Washington, Seattle, Washington 98195, USA.
Phys Rev Lett. 2016 Dec 9;117(24):240601. doi: 10.1103/PhysRevLett.117.240601. Epub 2016 Dec 7.
We examine localization phenomena associated with generic, high entropy, states of a translation-invariant, one-dimensional spin ladder. At early times, we find slow growth of entanglement entropy consistent with the known phenomenology of many-body localization in disordered, interacting systems. At intermediate times, however, anomalous diffusion sets in, leading to full spin polarization decay on an exponentially activated time scale. We identify a single length scale which parametrically controls both the spin transport times and the apparent divergence of the susceptibility to spin glass ordering. Ultimately, at the latest times, the exponentially slow anomalous diffusion gives way to diffusive thermal behavior. We dub the intermediate dynamical behavior, which persists over many orders of magnitude in time, quasi-many-body localization.
我们研究了与平移不变的一维自旋梯子的一般、高熵态相关的局域化现象。在早期，我们发现纠缠熵的缓慢增长，这与无序相互作用系统中多体局域化的已知现象学一致。然而，在中间时刻，反常扩散开始出现，导致在指数激活的时间尺度上自旋完全极化衰减。我们确定了一个单一的长度尺度，它参数化地控制了自旋输运时间和对自旋玻璃有序化的磁化率的明显发散。最终，在最晚时刻，指数缓慢的反常扩散让位于扩散热行为。我们将这种在时间上持续多个数量级的中间动力学行为称为准多体局域化。
