论文标题
在交换处的各向同性旋转链中的多体定位不完美
Imperfect Many-Body Localization in Exchange-Disordered Isotropic Spin Chains
论文作者
论文摘要
我们研究各向同性海森堡旋转链中的多体定位，局部交换参数受到淬灭的疾病。这样的系统通过全球su（2）转基金的不变性在其哈密顿量中纳入了非亚伯对称性。即使在存在牢固的疾病的情况下，非亚伯对称性也会阻止多体局部相位的出现。我们报告了使用精确的对角线化的数值研究，用于公共旋转长度1/2和1的链。平均的连续GAP比率显示出与从小小的疾病强度到不完全局部局部相位较强疾病的不完全局部化相位的交叉兼容的过渡。平均连续隙比的样本对样本差异在过渡时显示最大值，并通过其缩放行为将不完全局部相位与完全多体局部相位。
We investigate many-body localization in isotropic Heisenberg spin chains with the local exchange parameters being subject to quenched disorder. Such systems incorporate a nonabelian symmetry in their Hamiltonian by an invariance under global SU(2)-rotations. Nonabelian symmetries are predicted to hinder the emergence of a many-body localized phase even in presence of strong disorder. We report on numerical studies using exact diagonalization for chains of common spin length 1/2 and 1. The averaged consecutive-gap ratios display a transition compatible with a crossover from an ergodic phase at small disorder strength to an incompletely localized phase at stronger disorder. The sample-to-sample variance of the averaged consecutive-gap ratio displays a maximum at the transition and distinguishes the incompletely localized phase from a fully many-body localized phase by its scaling behavior.
