Solution of one-dimensional Bose Hubbard model in large-$U$ limit

Abstract

The one-dimensional Bose-Hubbard model in large-U limit has been studied via reducing and mapping the Hamiltonian to a simpler one. The eigenstates and eigenvalues have been obtained exactly in the subspaces with fixed numbers of single-and double-occupancies but without multipleoccupancies, and the thermodynamic properties of the system have been calculated further. These eigenstates and eigenvalues also enable us to develop a new perturbation treatment of the model, with which the ground-state energy has been calculated exactly to first order in 1/U .