Localization-protected order in spin chains with non-Abelian discrete symmetries
Localization-protected order in spin chains with non-Abelian discrete symmetries
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DOI：
10.1103/physrevb.98.064203
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发表时间：
2018-08-14
影响因子：
3.7
通讯作者：
Parameswaran, S. A.
中科院分区：
文献类型：
--
作者：
Friedman, Aaron J.;Vasseur, Romain;Parameswaran, S. A.
研究了一维三态随机量子Potts模型的非平衡相结构。这种自旋链的特征是一个非阿贝尔D-3对称性，最近被认为与保持对称性的多体定域(MBL)相的存在不相容。利用精确对角化和有限尺寸标度分析，我们发现该模型在强无序时支持两个截然不同的破缺对称性的MBL相，它们要么破坏Z(3)钟对称性，要么破坏Z(2)手征对称性。在对偶形式下，我们的结果表明存在一个稳定的有限温度拓扑相，具有MBL保护的副费米子端零模。当我们发现弱无序的热对称性保持机制时，在强无序的标度分析指向两个截然不同的破对称MBL相之间的无限随机性临界点。
We study the nonequilibrium phase structure of the three-state random quantum Potts model in one dimension. This spin chain is characterized by a non-Abelian D-3 symmetry recently argued to be incompatible with the existence of a symmetry-preserving many-body localized (MBL) phase. Using exact diagonalization and a finite-size scaling analysis, we find that the model supports two distinct broken-symmetry MBL phases at strong disorder that either break the Z(3) clock symmetry or a Z(2) chiral symmetry. In a dual formulation, our results indicate the existence of a stable finite-temperature topological phase with MBL-protected parafermionic end zero modes. While we find a thermal symmetry-preserving regime for weak disorder, scaling analysis at strong disorder points to an infinite-randomness critical point between two distinct broken-symmetry MBL phases.