Quasiparticle scattering by quantum phase slips in one-dimensional superfluids

TL;DR

This paper investigates how quantum phase slips in one-dimensional superfluids generate momentum and how this process is suppressed or facilitated by interactions with quasiparticles, revealing new insights into superfluid dynamics.

Contribution

It introduces the concept that momentum transfer during quantum phase slips is suppressed in uniform Bose gases and explores the interplay between quasiparticle scattering and disorder in BCS superfluids.

Findings

QPS rate is exponentially suppressed in uniform Bose gases due to momentum transfer requirements.

In BCS superfluids, momentum can be transferred to fermionic quasiparticles, affecting QPS dynamics.

Interplay between quasiparticle scattering and disorder influences superfluid behavior.

Abstract

Quantum phase slips (QPS) in narrow superfluid channels generate momentum by unwinding the supercurrent. In a uniform Bose gas, this momentum needs to be absorbed by quasiparticles (phonons). We show that this requirement results in an additional exponential suppression of the QPS rate (compared to the rate of QPS induced by a sharply localized perturbation). In BCS-paired fluids, momentum can be transferred to fermionic quasiparticles, and we find an interesting interplay between quasiparticle scattering on QPS and on disorder.