Antiferromagnetic spinor condensates in a two-dimensional optical lattice

TL;DR

This paper demonstrates how a two-dimensional optical lattice can control spin dynamics and phase transitions in spinor condensates, revealing tunable phases and a phenomenological model that matches experimental data.

Contribution

It introduces a method to tune spinor condensate phases using a 2D optical lattice and presents a semi-quantitative model without adjustable parameters.

Findings

Observation of lattice-tuned spin population oscillations

Detection of a phase transition from polar to broken-axisymmetry phase

Steady states depend sigmoidally on lattice depth and exponentially on magnetic field

Abstract

We experimentally demonstrate that spin dynamics and the phase diagram of spinor condensates can be conveniently tuned by a two-dimensional optical lattice. Spin population oscillations and a lattice-tuned separatrix in phase space are observed in every lattice where a substantial superfluid fraction exists. In a sufficiently deep lattice, we observe a phase transition from a longitudinal polar phase to a broken-axisymmetry phase in steady states of lattice-confined spinor condensates. The steady states are found to depend sigmoidally on the lattice depth and exponentially on the magnetic field. We also introduce a phenomenological model that semi-quantitatively describes our data without adjustable parameters.