Spin and Charge Transport of Multiorbital Quantum Spin Hall Insulators

The fabrication of bismuthene on top of SiC paved the way for substrate engineering of room temperature quantum spin Hall insulators made of group V atoms. We perform large-scale quantum transport calculations in these two-dimensional (2D) materials to analyze the rich phenomenology that arises from the interplay between topology, disorder, valley, and spin degrees of freedom. For this purpose, we consider a minimal multiorbital real-space tight-binding Hamiltonian and use a Chebyshev polynomial expansion technique. We discuss how the quantum spin Hall states are affected by disorder, sublattice resolved potential, and Rashba spin-orbit coupling. It is also shown that these materials can be driven to a topological Anderson insulator phase by sufficiently strong disorder.