论文标题
通过研究状态对边界条件的敏感性来表征多体定位
Characterizing The Many-Body Localization via Studying State Sensitivity to Boundary Conditions
论文作者
论文摘要
我们介绍了基于系统对边界条件的敏感性在离域和局部相之间多体相变的新颖特征。特别是，我们将边界条件从周期性变为反碘，并计算系统能量的变化和相应能量窗口中单粒子密度矩阵特征值的变化。我们采用典型模型来研究MBL，这是一种具有最接近邻邻逆变的费米的一维障碍系统，在现场能量上将疾病作为随机性引入。通过数值计算单粒子密度矩阵的系统能量和特征值的变化，我们观察到在局部状态下，这两个偏移都在消失。而在扩展方向上，这两个偏移都在相应级别间距的顺序上。我们还将相变的这些特征应用于除最近的邻居相互作用之外具有下一个邻居相互作用的情况，并研究了其对过渡的影响。
We introduce novel characterizations for many-body phase transitions between delocalized and localized phases based on the system's sensitivity to boundary conditions. In particular, we change boundary conditions from periodic to antiperiodic and calculate shift in the system's energy and shifts in the single-particle density matrix eigenvalues in the corresponding energy window. We employ the typical model for studying MBL, a one-dimensional disordered system of fermions with nearest-neighbor repulsive interaction where disorder is introduced as randomness on on-site energies. By calculating numerically the shifts in the system's energy and eigenvalues of the single-particle density matrix, we observe that in the localized regime, both shifts are vanishing; while in the extended regime, both shifts are on the order of the corresponding level spacing. We also applied these characterizations of the phase transition to the case of having next-nearest-neighbor interactions in addition to the nearest-neighbor interactions, and studied its effect on the transition.
