Fermionisation dynamics of a strongly interacting 1D Bose gas after an interaction quench

TL;DR

This paper investigates the non-equilibrium dynamics of a 1D Bose gas after a sudden interaction change, revealing rapid local thermalization and slower non-local correlation equilibration.

Contribution

It demonstrates that local correlations quickly reach steady states resembling thermal ensembles, while non-local correlations take longer, highlighting the role of integrability and propagation velocity.

Findings

Local correlations stabilize quickly, resembling thermal equilibrium.

Non-local correlations equilibrate over longer timescales.

Steady states are close to finite temperature grand canonical predictions.

Abstract

We study the dynamics of a one-dimensional Bose gas after a sudden change of the interaction strength from zero to a finite value using the numerical time-evolving block decimation (TEBD) algorithm. It is shown that despite the integrability of the system, local quantities such as the two-particle correlation $g^{(2)}(x,x)$ attain steady state values in a short characteristic time inversely proportional to the Tonks parameter $\gamma$ and the square of the density. The asymptotic values are very close to those of a finite temperature grand canonical ensemble with a local temperature corresponding to initial energy and density. Non-local density-density correlations on the other hand approach a steady state on a much larger time scale determined by the finite propagation velocity of oscillatory correlation waves.