Universal damping behavior of dipole oscillations of one-dimensional ultracold gases induced by quantum phase slips

TL;DR

This paper investigates how quantum phase slips cause damping in dipole oscillations of 1D ultracold gases, revealing universal behaviors and a key relation between damping rate and phase-slip nucleation rate.

Contribution

It establishes a fundamental relation between damping rate and phase-slip rate and demonstrates universal crossover behavior in damping at finite temperatures.

Findings

Damping rate $G$ is proportional to phase-slip rate $\Gamma$ divided by flow velocity $v$.

Damping in 1D Bose gases is primarily due to quantum phase slips.

Damping rate exhibits universal crossover behavior with temperature and flow velocity.

Abstract

We study superflow decay via quantum phase slips in trapped one-dimensional (1D) quantum gases through dipole oscillations induced by sudden displacement of the trapping potential. We find the relation between the damping rate of the dipole oscillation $G$ and the phase-slip nucleation rate $\Gamma$ as $G\propto \Gamma/v$, where $v$ is the flow velocity. This relation allows us to show that damping of 1D Bose gases in optical lattices, which has been extensively studied in experiment, is due to quantum phase slips. It is also found that the damping rate versus the flow velocity obeys the scaling formula for an impurity potential even in the absence of an explicit impurity. We suggest that the damping rate at a finite temperature exhibits a universal crossover behavior upon changing the flow velocity.