Quantum phase transition in a 2D atomic Bose gas with a g-wave Feshbach resonance

TL;DR

This paper investigates quantum phase transitions in a quasi-2D atomic Bose gas with a g-wave Feshbach resonance, revealing two distinct phase transitions and the effects of resonance beyond mean-field theory.

Contribution

It provides the first detailed analysis of phase transitions involving atomic and molecular condensates with g-wave Feshbach resonance beyond mean-field approximation.

Findings

Identified two phase transitions: atomic BEC to coexistence, and coexistence to molecular BEC.

Resonance effects appear only beyond mean-field, altering phase boundaries.

Determined the phase diagram and atomic-molecular ratio at zero temperature.

Abstract

Recent repoet on the formation of two-dimensional Bose-Einstein condensates (BECs) of spinning g-wave molecules is surprise. Here we study quantum phase transition in the quasi-2D atomic Bose gas with a g-wave Feshbach resonance, and show that there are two phase transitions in this system: from a phase with only a atomic Bose-Einstein condensate to a phase with coexistence of atomic and molecular condensation and from the coexistence phase to a phase with only a molecular Bose-Einstein condensate. We show that the g-wave resonance Feshbach has two features in the phase transitions, a phase with only a atomic Bose-Einstein condensate is no longer forbidden and resonance effects appear only at levels beyond the mean-field. We determine the T=0 beyond mean-field phase diagram of the gas as a function of magnetic field and molecular condensation density. We also detemine the ratio of atomic to molecular condensation in the coexistence phase, which can be tested in experiments.