Maximally localized Wannier functions for describing a topological phase transition in stanene

Starting from first-principles calculations on pristine stanene and using maximally localized Wannier functions (MLWFs), we analyze the different phases of the system when it is driven to a topological phase transition. The transition is achieved by a continuous parameter represented by an external electric field epsilon(z) as a generic inversion-symmetry-breaking term. We also compare the results with those of a multiorbital tight-binding (TB) model for stanene, whose hopping integrals are determined by Slater-Koster parameters. The system is in a topological (trivial) phase for epsilon(z) < epsilon(c) (epsilon(z) > epsilon(c)). We obtain that the critical field is epsilon(c) similar or equal to 0.69 eV/angstrom for the more realistic MLWF compared to epsilon(c) similar or equal to 0.15 eV/angstrom in the TB model. This suggests a larger stability of the topological phase of stanene when deposited on inert substrates.