Superfluid-Mott Insulator Transition of Spin-1 Bosons in an Optical Lattice

TL;DR

This paper investigates the phase transition between superfluid and Mott insulator states in spin-1 bosons within an optical lattice, revealing a polar superfluid phase and enhanced Mott insulator stability at even atom numbers.

Contribution

It presents a mean-field phase diagram for spin-1 bosons, highlighting the stabilization of the Mott insulator phase at even atom counts, which is a novel insight.

Findings

Superfluid phase is a polar state.

Mott insulator is stabilized at even atom numbers.

Phase diagram obtained via mean-field approximation.

Abstract

We have studied superfluid-Mott insulating transition of spin-1 bosons interacting antiferromagnetically in an optical lattice. We have obtained the zero-temperature phase diagram by a mean-field approximation and have found that the superfluid phase is to be a polar state as a usual trapped spin-1 Bose gas. More interestingly, we have found that the Mott-insulating phase is strongly stabilized only when the number of atoms per site is even.