Electronic Properties And Quasiparticle Model Of Monolayer Mosi2n4

In this paper, we theoretically investigated the electronic properties of monolayer MoSi2N4 by combining first-principles calculations and symmetry analyses. Spin-orbital coupling resulted in band splitting, whereas a horizontal mirror symmetry constrained the spin polarization to be along the z direction. In addition, a three-band tight-binding model was constructed to describe the low-energy quasiparticle states of monolayer MoSi2N4, which can be generalized to strained MoSi2N4 and its derivatives. The calculations using the tight-binding model showed an undamped root q-dependent plasmon mode, consistent with the results of first-principles calculations. The developed model is suitable for future theoretical and numerical investigations of low-energy properties in MoSi2N4 family materials. Furthermore, the study of the electronic properties of monolayer MoSi2N4 paves a way for its applications in spintronics and plasmonics.