Z2topological invariants in two dimensions from quantum Monte Carlo

Thomas C. Lang, Andrew M. Essin, Victor Gurarie, Stefan Wessel
2013 Physical Review B  
We employ quantum Monte Carlo techniques to calculate the $Z_2$ topological invariant in a two-dimensional model of interacting electrons that exhibits a quantum spin Hall topological insulator phase. In particular, we consider the parity invariant for inversion-symmetric systems, which can be obtained from the bulk's imaginary-time Green's function after an appropriate continuation to zero frequency. This topological invariant is used here in order to study the trivial-band to
more » ... to topological-insulator transitions in an interacting system with spin-orbit coupling and an explicit bond dimerization. We discuss the accessibility and behavior of this topological invariant within quantum Monte Carlo simulations.
doi:10.1103/physrevb.87.205101 fatcat:syhdzjqv7rerbpjdfxbikm7ajy