Quantum Phases of the Extended Bose-Hubbard Hamiltonian: Possibility of a Supersolid State of Cold Atoms in Optical Lattices

TL;DR

This paper explores the theoretical potential of using excited states in optical lattices to realize extended Bose-Hubbard models, revealing a rich phase diagram including supersolid states through mean field analysis.

Contribution

It introduces the concept of utilizing higher bands in optical lattices to simulate extended-range interactions in Bose-Hubbard models, expanding the possibilities for quantum phase engineering.

Findings

Extended Bose-Hubbard models can support supersolid phases.

Metastable states are achievable within specific parameter regimes.

Higher bands enable richer phase diagrams in cold atom systems.

Abstract

Cold atom optical lattices typically simulate zero-range Hubbard models. We discuss the theoretical possibility of using excited states of optical lattices to generate extended range Hubbard models. We find that bosons confined to higher bands of optical lattices allow for a rich phase diagram, including the supersolid phase. Using Gutzwiller, mean field theory we establish the parameter regime necessary to maintain metastable states generated by an extended Bose-Hubbard model.