Interaction quantum quenches in the one-dimensional Fermi-Hubbard model with spin imbalance

TL;DR

This paper investigates the non-equilibrium dynamics of the one-dimensional Fermi-Hubbard model after quantum quenches, revealing how FFLO correlations emerge, evolve, and are suppressed under different interaction protocols.

Contribution

It provides the first detailed analysis of FFLO correlation dynamics in the 1D Fermi-Hubbard model using advanced numerical methods, including the effects of ramps versus quenches.

Findings

FFLO correlations emerge after quenches from non-interacting to attractive regimes.

Double occupancy peaks when interaction strength matches the bandwidth.

Short ramps can effectively erase FFLO features in pair momentum distributions.

Abstract

Using the time-dependent density matrix renormalization group method and exact diagonalization, we study the non-equilibrium dynamics of the one-dimensional Fermi-Hubbard model following a quantum quench or a ramp of the onsite interaction strength. For quenches from the non-interacting to the attractive regime, we investigate the dynamical emergence of Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) correlations, which at finite spin polarizations are the dominant two-body correlations in the ground state, and their signatures in the pair quasi-momentum distribution function. We observe that the post-quench double occupancy exhibits a maximum as the interaction strength becomes of the order of the bandwidth. Finally, we study quenches and ramps from attractive to repulsive interactions, which imprint FFLO correlations onto repulsively bound pairs. We show that a quite short ramp time is sufficient to wipe out the characteristic FFLO features in the post-quench pair momentum distribution functions.