Multicriticality of Class D Disordered Topological Insulator in a Two-dimensional Lattice Model

A two-dimensional tight-binding model of a disordered topological insulator in class D is numerically studied by the transfer matrix method and the kernel polynomial expansion (KPE). We find a phase diagram exhibiting topological insulator (TI), diffusive metal (DM) and Anderson insulator (AI) phases. We clarify the critical behavior of the localization length, conductivity and density of states at a tricritical point [1-3], as well as the universality class of the DM-AI transition and TI-DM transitions. We compare our numerical results with a two-loop renormalization group study of 2D Dirac fermions with random mass [4].

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[4] Zhiming Pan et al., in preparation.