Nonequilibrium dynamics in one-dimensional strongly interacting two-component gases

TL;DR

This paper derives exact determinant formulas for correlation functions in a one-dimensional two-component Fermi gas with strong interactions, enabling analysis of nonequilibrium dynamics, including quantum quenches and hydrodynamization.

Contribution

It introduces new determinant representations for correlation functions in the impenetrable Gaudin-Yang model, applicable to both equilibrium and nonequilibrium scenarios with trapping potentials.

Findings

Exact numerical analysis of quantum Newton's cradle dynamics.

Prediction of a many-body bounce effect in momentum distribution.

Equivalence to a multicomponent Lenard's formula for equal-time correlators.

Abstract

The derivation of determinant representations for the space-, time-, and temperature-dependent correlation functions of the impenetrable Gaudin-Yang model in the presence of a trapping potential is presented. These representations are valid in both equilibrium and nonequilibrium scenarios like the ones initiated by a sudden change of the confinement potential. In the equal-time case our results are shown to be equivalent to a multicomponent generalization of Lenard's formula from which Painlev\'e transcendent representations for the correlators can be obtained in the case of harmonic trapping and Dirichlet and Neumann boundary conditions. For a system in the quantum Newton's cradle setup the determinant representations allow for an exact numerical investigation of the dynamics and even hydrodynamization which is outside the reach of Generalized Hydrodynamics or other approximate methods. In the case of a sudden change in the trap's frequency we predict a many-body bounce effect, not present in the evolution of the density profile, which causes a nontrivial periodic narrowing of the momentum distribution with amplitude depending on the statistics of the particles.