Non-equilibrium dynamics of an ultracold Bose gas under a multi-pulsed quantum quench in interaction

TL;DR

This paper explores the non-equilibrium behavior of a weakly-interacting Bose gas subjected to multiple interaction quenches, revealing increased excitations with more quenches and connecting two-body correlations to experimental Tan's contact measurements.

Contribution

It introduces a detailed analysis of multi-pulsed quantum quenches in Bose gases, highlighting their effectiveness in studying many-body dynamics beyond single quenches.

Findings

More quenches lead to higher excitations.

Multi-pulsed quenches are more effective than single quenches.

Two-body correlations can probe Tan's contact experimentally.

Abstract

We investigate the nonequilibrium dynamical properties of a weakly-interacting Bose gas at zero temperature under the multi-pulsed quantum quench in interaction by calculating one-body, two-body correlation functions and Tan's contact of the model system. The multi-pulsed quench is represented as follows: first suddenly quenching the interatomic interaction from $g_{i}$ to $g_{f}$ at time $t=0$, holding time $t$, and then suddenly quenching interaction from $g_{f}$ back to $g_{i}$, holding the time $t$ sequence $n$ times. In particular, two typical kinds of quenching parameters are chosen, corresponding to $(g_{i}/g_{f}>1)$ and $(g_{i}/g_{f}<1)$ respectively. We find that the more the quenching times of $n$ are, the more the excitations are excited, which suggests that the multi-pulsed QQ is more powerful way of studying the non-equilibrium dynamics of many-body quantum system than the `one-off' quantum quench. Finally, we discuss the ultra-short-range properties of the two-body correlation function after the $n$th quenching, which can be used to probe the `Tan'scontact' in experiments. All our calculations can be tested in current cold atom experiments.