1D to 3D Crossover of a Spin-Imbalanced Fermi Gas

TL;DR

This study explores the transition of a spin-imbalanced Fermi gas from one-dimensional to three-dimensional behavior by tuning lattice parameters, revealing phase boundary inversions and a universal crossover point.

Contribution

It provides the first detailed experimental characterization of the 1D to 3D crossover in a spin-imbalanced Fermi gas using in situ imaging and scaling analysis.

Findings

Phase separation and phase boundary inversion between 1D and 3D.

Universal crossover point at scaled tunneling of approximately 0.025.

Data collapse achieved through scaling tunneling with pair binding energy.

Abstract

We have characterized the one-dimensional (1D) to three-dimensional (3D) crossover of a two-component spin-imbalanced Fermi gas of 6-lithium atoms in a 2D optical lattice by varying the lattice tunneling and the interactions. The gas phase separates, and we detect the phase boundaries using in situ imaging of the inhomogeneous density profiles. The locations of the phases are inverted in 1D as compared to 3D, thus providing a clear signature of the crossover. By scaling the tunneling rate with respect to the pair binding energy, we observe a collapse of the data to a universal crossover point at a scaled tunneling value of 0.025(7).