Crossovers in Unitary Fermi Systems

TL;DR

This paper reviews the universal behavior and phase transitions in unitary Fermi systems across various interaction regimes, models, and physical contexts, highlighting the theoretical frameworks and differences in lattice and solid-state systems.

Contribution

It provides a comprehensive analysis of crossovers, phase transitions, and universal parameters in Fermi systems using multiple models and applies these insights across different physical systems.

Findings

Description of BCS-BEC crossover and ferromagnetic transition

Calculation of universal parameters within various models

Discussion of differences between optical lattices and cuprates

Abstract

Universality and crossover is described for attractive and repulsive interactions where, respectively, the BCS-BEC crossover takes place and a ferromagnetic phase transition is claimed. Crossovers are also described for optical lattices and multicomponent systems. The crossovers, universal parameters and phase transitions are described within the Leggett and NSR models and calculated in detail within the Jastrow-Slater approximation. The physics of ultracold Fermi atoms is applied to neutron, nuclear and quark matter, nuclei and electrons in solids whenever possible. Specifically, the differences between optical lattices and cuprates is discussed w.r.t. antiferromagnetic, d-wave superfluid phases and phase separation.