Excitation spectrum and momentum distribution of the ionic Bose-Hubbard model

Abstract We investigate the excitation spectrum and momentum distribution of ionic Bose–Hubbard model by standard basis operator method. derive Green’s functions in random phase approximation Mott insulator, superfluid, charge density wave, supersolid phases. The has gapped modes gapless Goldstone superfluid show that a peak at zone corner wave close to boundary. In addition, we demonstrate can be explained spectral weights hole modes.