First-order superfluid to Mott-insulator phase transitions in spinor condensates

TL;DR

This paper reports the experimental observation of first-order superfluid to Mott-insulator phase transitions in spinor Bose-Einstein condensates, highlighting the role of quadratic Zeeman energy and mean field theory insights.

Contribution

It demonstrates the first experimental evidence of first-order phase transitions in spinor condensates and introduces tuning quadratic Zeeman energy as a new method to control these transitions.

Findings

Hysteresis observed across phase transitions

Significant heating during phase changes

Transition nature depends on quadratic Zeeman energy ratio

Abstract

We observe evidence of first-order superfluid to Mott-insulator quantum phase transitions in a lattice-confined antiferromagnetic spinor Bose-Einstein condensate. The observed signatures include hysteresis effect and significant heatings across the phase transitions. The nature of the phase transitions is found to strongly depend on the ratio of the quadratic Zeeman energy to the spin-dependent interaction. Our observations are qualitatively understood by the mean field theory, and in addition suggest tuning the quadratic Zeeman energy is a new approach to realize superfluid to Mott-insulator phase transitions.