Spreading of correlations in a quenched repulsive and attractive one dimensional lattice system

TL;DR

This paper investigates how correlations spread over time in a one-dimensional lattice system after a sudden change in interactions, revealing light-cone behavior, velocity saturation, and complex dynamics depending on interaction type and initial state.

Contribution

It provides a detailed analysis of correlation spreading in a quenched 1D lattice system using time-dependent DMRG, highlighting new behaviors in both repulsive and attractive regimes.

Findings

Correlation spreading exhibits light-cone behavior.

Spreading velocity increases with interaction strength and saturates.

Complex dynamics such as bound state formation occur in certain regimes.

Abstract

We study the real time evolution of the correlation functions in a globally quenched interacting one dimensional lattice system by means of time adaptive density matrix renormalization group. We find a clear light-cone behavior quenching the repulsive interaction from the gapped density wave regime. The spreading velocity increases with the final values of the interaction and then saturates at a certain finite value. In the case of a Luttinger liquid phase as the initial state, for strong repulsive interaction quenches, a more complex dynamics occurs as a result of bound state formations. From the other side in the attractive regime, depending on where connected correlation functions are measured, one can observe a delay in the starting time evolution and a coexistence of ballistic and localized signals.