论文标题
恢复的Heisenberg链中的产品状态
Reviving product states in the disordered Heisenberg chain
论文作者
论文摘要
当在简单的初始条件下制备通用量子系统时,通常会朝着可以通过热合奏描述的状态平衡。已知的例外是非凝聚力且不热化的局部系统,但是局部可观察物仍然被认为是固定的。在这里,我们证明了这一一般图像是不完整的,这些图像构建了产品状态,这些状态具有周期性的高保真复兴,并无限期地振荡着全波函数和局部可观察物。该系统既不能平衡也没有热量。这类似于由于多体疤痕和挑战当前MBL现象学的挑战,例如纠缠熵的对数生长,这与弱恐惧症破裂的现象类似。为了支持我们的主张,我们将分析论点与无序的Heisenberg链的大规模张量网络数字相结合。我们的结果任意长期存在于160个站点的链条上,直到机器精度。
When a generic quantum system is prepared in a simple initial condition, it typically equilibrates toward a state that can be described by a thermal ensemble. A known exception are localized systems which are non-ergodic and do not thermalize, however local observables are still believed to become stationary. Here we demonstrate that this general picture is incomplete by constructing product states which feature periodic high-fidelity revivals of the full wavefunction and local observables that oscillate indefinitely. The system neither equilibrates nor thermalizes. This is analogous to the phenomenon of weak ergodicity breaking due to many-body scars and challenges aspects of the current MBL phenomenology, such as the logarithmic growth of the entanglement entropy. To support our claim, we combine analytic arguments with large-scale tensor network numerics for the disordered Heisenberg chain. Our results hold for arbitrarily long times in chains of 160 sites up to machine precision.