paper

Stability of current-carrying states in hard-core bosons with long-range hopping on a square lattice

arXiv:2511.14260 · doi:10.1103/xvx2-n5j2

Abstract

We investigate the stability of current-carrying states with quasi-momentum in the Bose-condensed phase of the hard-core Bose-Hubbard model on a square lattice, where particles transfer between two sites separated by distance with hopping amplitude decaying algebraically with as . Using a mean-field theory, we analyze the excitation spectrum and determine the critical quasi-momenta associated with Landau and dynamical instabilities. We find that the long-range hopping suppresses the critical quasi-momenta and makes them vanish at . Near , we show that the critical quasi-momentum for the dynamical instability exhibits the scaling behavior with , where the scaling exponent explicitly depends on , as a consequence of the long-range nature of the hopping.

Revised to match the published version. 10 pages, 7 figures

References in corpus (23)