Time evolution of correlations in strongly interacting fermions after a quantum quench

TL;DR

This paper investigates how density correlations evolve over time in strongly interacting spinless fermions on a 1D lattice after a sudden change in interaction strength, revealing light-cone-like behavior and domain wall formation.

Contribution

It provides the first detailed numerical analysis of correlation dynamics post-quench in strongly interacting fermionic systems using adaptive tDMRG.

Findings

Ballistic light-cone-like correlation spreading observed

Stable domain walls form in certain quench regimes

Different behaviors depending on initial and final phases

Abstract

Using the adaptive time-dependent density matrix renormalization group, we study the time evolution of density correlations of interacting spinless fermions on a one-dimensional lattice after a sudden change in the interaction strength. Over a broad range of model parameters, the correlation function exhibits a characteristic light-cone-like time evolution representative of a ballistic transport of information. Such behavior is observed both when quenching an insulator into the metallic region and also when quenching within the insulating region. However, when a metallic state beyond the quantum critical point is quenched deep into the insulating regime, no indication for ballistic transport is observed. Instead, stable domain walls in the density correlations emerge during the time evolution, consistent with the predictions of the Kibble-Zurek mechanism.