Coupled-cluster theory of a gas of strongly-interacting fermions in the dilute limit

TL;DR

This paper applies coupled-cluster theory to analyze the ground-state properties of a dilute, strongly-interacting fermionic gas, revealing universal behaviors and spectral gaps, with results depending primarily on system dimensionality.

Contribution

It demonstrates that coupled-cluster expansion naturally captures universality, spectral gaps, and s-wave approximation validity in strongly-interacting fermion gases.

Findings

Properties like universality and spectral gaps emerge naturally in CCE.

Ground-state energy density depends on a single parameter related to dimensionality.

The approach is valid in the zero-density limit for strongly-interacting fermions.

Abstract

We study the ground-state properties of a dilute gas of strongly-interacting fermions in the framework of the coupled-cluster expansion (CCE). We demonstrate that properties such as universality, opening of a gap in the excitation spectrum and applicability of s-wave approximations appear naturally in the CCE approach. In the zero-density limit, we show that the ground-state energy density depends on only one parameter which in turn may depend at most on the spatial dimensionality of the system.