论文标题
跟踪无序系统的时间演变中的局部性
Tracking locality in time evolution of disordered systems
论文作者
论文摘要
使用局部密度相关函数作为一维自旋系统，我们引入了相关函数差异（CFD），该函数差异（CFD）将给定站点上的相关性在整个大小$ l $的系统及其限制到$ \ ell <l $站点之间进行比较。我们表明，CFD通过考虑无序XXZ旋转链中的ergodic，Anderson和多体局部制度的示例，提供了有关量子多体系统中信息传输的有用信息。在奇异阶段，我们发现CFD的繁殖比自旋传输更快，但比Lieb-Robinson结合所隐含的弹道传播慢。相反，在本地情况下，我们揭示了CFD的指数缓慢放松。讨论了CFD与其他可观察到系统中非本地相关性的连接。
Using local density correlation functions for a one-dimensional spin system, we introduce a correlation function difference (CFD) which compares correlations on a given site between a full system of size $L$ and its restriction to $\ell<L$ sites. We show that CFD provides useful information on transfer of information in quantum many-body systems by considering the examples of ergodic, Anderson, and many-body localized regimes in disordered XXZ spin chain. In the ergodic phase, we find that the propagation of CFD is asymptotically faster than the spin transport but slower than the ballistic propagation implied by the Lieb-Robinson bound. In contrast, in the localized cases, we unravel an exponentially slow relaxation of CFD. Connections between CFD and other observables detecting non-local correlations in the system are discussed.
