Universality in one-dimensional fermions at finite temperature: Density, pressure, compressibility, and contact

TL;DR

This paper uses lattice Monte Carlo methods to study thermodynamic properties of one-dimensional fermions at finite temperature, revealing universal behaviors and strong-coupling effects relevant for ultracold atomic systems.

Contribution

It provides the first comprehensive finite-temperature calculations of density, pressure, compressibility, and contact for 1D fermions, including virial coefficients, with implications for experiments.

Findings

Universal predictions for ultracold atomic systems.

Strong-coupling regime significantly alters thermodynamics.

Excellent agreement of virial coefficients with lattice results.

Abstract

We present finite-temperature, lattice Monte Carlo calculations of the particle number density, compressibility, pressure, and Tan's contact of an unpolarized system of short-range, attractively interacting spin-1/2 fermions in one spatial dimension, i.e., the Gaudin-Yang model. In addition, we compute the second-order virial coefficients for the pressure and the contact, both of which are in excellent agreement with the lattice results in the low-fugacity regime. Our calculations yield universal predictions for ultracold atomic systems with broad resonances in highly constrained traps. We cover a wide range of couplings and temperatures and find results that support the existence of a strong-coupling regime in which the thermodynamics of the system is markedly different from the noninteracting case. We compare and contrast our results with identical systems in higher dimensions.