Fermi-to-Bose crossover in a trapped quasi-2D gas of fermionic atoms

TL;DR

This paper reviews experimental and theoretical studies of the Fermi-to-Bose crossover in a trapped quasi-2D ultracold atomic gas, highlighting the unique physics and critical phenomena associated with this transition.

Contribution

It provides a comprehensive overview of recent experimental demonstrations and theoretical models of the Fermi-to-Bose crossover in 2D ultracold gases, emphasizing the system's unique quantum statistics.

Findings

Demonstration of the Fermi-to-Bose crossover in 2D ultracold gases

Comparison of experimental data with simple and advanced theoretical models

Insights into critical phenomena in 2D quantum gases

Abstract

Physics of many-body systems where particles are restricted to move in two spatial dimensions is challenging and even controversial: On one hand, neither long-range order nor Bose condensation may appear in infinite uniform 2D systems at finite temperature, on the other hand this does not prohibit superfluidity or superconductivity. Moreover, 2D superconductors, such as cuprates, are among the systems with highest critical temperatures. Ultracold atoms are a platform for studying 2D physics. Uniquely to other physical systems, quantum statistics may be completely changed in an ultracold gas: an atomic Fermi gas may be smoothly crossed over into a gas of Bose molecules (or dimers) by tuning interatomic interactions. We review recent experiments where such crossover has been demonstrated as well as critical phenomena in the Fermi-to-Bose crossover. We also present simple theoretical models describing the gas at different points of the crossover and compare the data to these and more advanced models.