Substrate screening approach for quasiparticle energies of two-dimensional interfaces with lattice mismatch

Two-dimensional (2D) materials are outstanding platforms for exotic physics and emerging applications by forming interfaces. In order to efficiently take into account the substrate screening in the quasiparticle energies of 2D materials, several theoretical methods have been proposed previously but are only applicable to interfaces of two systems' lattice constants with certain integer proportion, which often requires a few percent of strain. In this work, we analytically showed the equivalence and distinction among different approximate methods for substrate dielectric matrices. We evaluated the accuracy of these methods by applying them to calculate quasiparticle energies of hexagonal boron nitride interface systems (heterojunctions and bilayers) and compared the results with explicit interface calculations. Most importantly, we developed an efficient and accurate interpolation technique for dielectric matrices that made quasiparticle energy calculations possible for arbitrarily mismatched interfaces free of strain, which is extremely valuable for practical applications.