Reduction of $\mathbb{Z}$ classification of a two-dimensional weak topological insulator - real-space DMFT study -

Abstract

One of the remarkable interaction effects on topological insulators is the reduction of topological classification in free-fermion systems. We address this issue in a bilayer honeycomb lattice model by taking into account temperature effects on the reduction. Our analysis, based on the real-space dynamical mean field theory, elucidates the following results. (i) Even when the reduction occurs, the winding number defined by the Green's function can take a nontrivial value at zero temperature. (ii) The winding number taking the nontrivial value becomes consistent with the absence of gapless edge modes due to Mott behaviors emerging only at the edges. (iii) Temperature effects can restore the gapless edge modes, provided that the energy scale of interactions is smaller than the bulk gap. In addition, we observe the topological edge Mott behavior only in some finite temperature region.

6.5 pages, 5 figures. Accepted for PRB

References in corpus (13)

• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Evidence of Majorana fermions in an Al - InAs nanowire topological superconductor
• Continuous-time Monte Carlo methods for quantum impurity models
• Quantum Monte Carlo Impurity Solver for Cluster DMFT and Electronic Structure Calculations in Adjustable Base
• Quantum spin Hall effect in a transition metal oxide Na2IrO3
• Hybridization expansion impurity solver: General formulation and application to Kondo lattice and two-orbital models
• Simplified topological invariants for interacting insulators
• Antiferromagnetic Order of Strongly Interacting Fermions in a Trap: Real-Space Dynamical Mean-Field Analysis
• Topological invariants and interacting one-dimensional fermionic systems
• Mott transition of fermionic atoms in a three-dimensional optical trap
• Symmetry Protected Topological States of Interacting Fermions and Bosons
• Strongly Correlated Topological Superconductors and Topological Phase Transitions via Green's Function
• CPT theorem and classification of topological insulators and superconductors