Spectral properties of one-dimensional Fermi systems after an interaction quench

TL;DR

This paper investigates the spectral signatures of one-dimensional Fermi systems after an interaction quench, revealing distinctive nonequilibrium features that can be experimentally detected through improved radio-frequency spectroscopy.

Contribution

It provides a detailed analysis of the spectral properties of Luttinger liquids post-quench, highlighting their unique nonequilibrium characteristics and potential experimental identification methods.

Findings

Spectral functions differ significantly from equilibrium states.

Distinctive line shapes serve as signatures of nonequilibrium Luttinger liquids.

Experimental detection via improved radio-frequency spectroscopy is feasible.

Abstract

We show that the single-particle spectral properties of gapless one-dimensional Fermi systems in the Luttinger liquid state reached at intermediate times after an abrupt quench of the two-particle interaction are highly indicative of the unusual nonequilibrium nature of this state. The line shapes of the momentum integrated and resolved spectral functions strongly differ from their ground state as well as finite temperature equilibrium counterparts. Using an energy resolution improved version of radio-frequency spectroscopy of quasi one-dimensional cold Fermi gases it should be possible to experimentally identify this nonequilibrium state by its pronounced spectral signatures.