Slow thermalization of exact quantum many-body scar states under perturbations
Slow thermalization of exact quantum many-body scar states under perturbations
复制标题
DOI：
10.1103/physrevresearch.2.033044
复制
发表时间：
2019-10
影响因子：
4.2
通讯作者：
Cheng-Ju Lin;A. Chandran;O. Motrunich
中科院分区：
文献类型：
--
作者：
Cheng-Ju Lin;A. Chandran;O. Motrunich
量子多体疤痕态是在热化系统中不满足本征态热化假说的特殊有限能量密度本征态。我们研究了精确多体疤痕状态在扰动下的命运。在小系统尺寸下，由微扰理论描述的变形疤痕状态仍然存在。然而，我们从非对角矩阵元素的有限尺寸缩放中争论它们在热力学极限下的最终热化。然而，我们通过数值和分析表明，在淬火实验中，伤痕的非热特性在参数化的时间内仍然存在。我们提出了一个严格的论点，即任何疤痕状态的热化时间的下限为$t^{*} \sim O(\lambda^{-1/(1+d)})$，其中$d$是系统的空间维度，$\lambda$是微扰强度。
Quantum many-body scar states are exceptional finite energy density eigenstates in an otherwise thermalizing system that do not satisfy the eigenstate thermalization hypothesis. We investigate the fate of exact many-body scar states under perturbations. At small system sizes, deformed scar states described by perturbation theory survive. However, we argue for their eventual thermalization in the thermodynamic limit from the finite-size scaling of the off-diagonal matrix elements. Nevertheless, we show numerically and analytically that the nonthermal properties of the scars survive for a parametrically long time in quench experiments. We present a rigorous argument that lower-bounds the thermalization time for any scar state as $t^{*} \sim O(\lambda^{-1/(1+d)})$, where $d$ is the spatial dimension of the system and $\lambda$ is the perturbation strength.