Fermi liquid theory of ultra-cold trapped Fermi gases: Implications for Pseudogap Physics and Other Strongly Correlated Phases

TL;DR

This paper demonstrates how Fermi liquid theory can be applied to ultra-cold Fermi gases, enabling exploration of strongly correlated phases and addressing debates about their normal state and magnetic properties.

Contribution

It introduces procedures for measuring and calculating Landau parameters in ultra-cold gases, extending Fermi liquid theory's applicability to these systems.

Findings

Normal state of unitary gas may be a Fermi liquid

Strong repulsive interactions could lead to ferromagnetism or localization

Framework for measuring position-dependent Landau parameters

Abstract

We show how Fermi liquid theory can be applied to ultra-cold Fermi gases, thereby expanding their "simulation" capabilities to a class of problems of interest to multiple physics sub-disciplines. We introduce procedures for measuring and calculating position dependent Landau parameters. This lays the ground work for addressing important controversial issues: (i) the suggestion that thermodynamically, the normal state of a unitary gas is indistinguishable from a Fermi liquid (ii) that a fermionic system with strong repulsive contact interactions is associated with either ferromagnetism or localization; this relates as well to $^3$He and its p-wave superfluidity.