Density–driven superfluid transition of the constrained bosons on a lattice

Abstract

We formulate the Landau theory and study its consequences for lattice bosons, which are stabilized by a three-body on-site constraint. This is relevant for experiments with cold atoms in optical lattices, where the presence of three-body dissipative loss processes renders the occupation number n for bosons on short timescales effectively constrained to n≤2. We elaborate on the Landau free energy expansion resulting from the Hamiltonian of bosons in the restricted Hilbert space, and present the phase diagram of the constrained Bose lattice gas.