Multicriticality of two-dimensional class-D disordered topological superconductors
Multicriticality of two-dimensional class-D disordered topological superconductors
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DOI：
10.1103/physrevb.104.184201
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发表时间：
2021-08
影响因子：
3.7
通讯作者：
Tong Wang;Zhiming Pan;T. Ohtsuki;I. Gruzberg;Ryuichi Shindou
中科院分区：
文献类型：
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作者：
Tong Wang;Zhiming Pan;T. Ohtsuki;I. Gruzberg;Ryuichi Shindou
对称D类二维无序拓扑超导体具有丰富的现象学和多相：扩散热金属（DTM）、安德森绝缘体（AI）和热量子霍尔（TQH）相（拓扑超导体）。我们数值研究了D类超导体晶格模型的相图，特别关注相之间的转变和相关的通用临界行为。我们证实了三相相交点上三临界点的存在及其排斥性。我们利用局域化长度、电导（或电导率）和态密度的数值计算来表征在不同临界点和三临界点处的临界行为。我们得出两个金属绝缘子跃迁（DTM-TQH和DTM-AI）属于同一通用性类，而三临界点（TCP）代表不同的通用性类。
A generic two-dimensional disordered topological superconductor in symmetry class D exhibits rich phenomenology and multiple phases: diffusive thermal metal (DTM), Anderson insulator (AI), and thermal quantum Hall (TQH) phase (a topological superconductor). We numerically investigate the phase diagram of a lattice model of such class D superconductor, specifically focusing on transitions between the phases and the associated universal critical behaviors. We confirm the existence of a tricritical point and its repulsive nature at the point on the phase diagram where the three phases meet. We characterize the critical behaviors at various critical points and the tricritical point using numerical evaluation of the localization length, the conductance (or conductivity), and the density of states. We conclude that the two metal-insulator transitions (DTM-TQH and DTM-AI) belong to the same universality class, whereas the tricritical point (TCP) represents a distinct universality class.