Synergistic Effect of Lattice Distortion and Random On-Site Energies in 2D Materials

Abstract

Two-dimensional quantum materials have attracted extensive attention since the discovery of single-layer graphene, partly due to the exotic physical properties of magic-angle twisted bilayer graphene. The nontrivial topology of band structures plays an essential role in the unique electronic properties due to strongly correlated electrons. Recently, structural amorphization was theoretically confirmed to induce topological orderrandom local distortion results in a random distribution of the electron interaction. Since structural distortion and chemical doping can change the on-site energies, we propose a new Hamiltonian to include the randomness in on-site energies and capture the effect of the Anderson localization on the emergence of topological insulating phases. We find that the randomness of on-site energies promotes the emergence of topological insulating phases and has a synergistic role with structural amorphization in the phase transition.