Superfluid flow above the critical velocity

TL;DR

This paper demonstrates that superfluidity can persist above the traditional critical velocity through quantum interference resonances, challenging existing understanding and enabling new applications in quantum sensing.

Contribution

It introduces a novel mechanism allowing superfluid flow above the critical velocity via quantum interference effects.

Findings

Superfluidity persists above the critical velocity due to quantum interference.

Resonance phenomena enable superfluid flow beyond traditional thresholds.

Potential applications in quantum metrology and rotation sensing.

Abstract

Superfluidity and superconductivity have been studied widely since the last century in many different contexts ranging from nuclear matter to atomic quantum gases. The rigidity of these systems with respect to external perturbations results in frictionless motion for superfluids and resistance-free electric current in superconductors. This peculiar behaviour is lost when external perturbations overcome a critical threshold, i.e. above a critical magnetic field or a critical current for superconductors. In superfluids, such as liquid helium or ultracold gases, the corresponding quantities are critical rotation rate and critical velocity, respectively. Enhancing the critical values is of great fundamental and practical value. Here we demonstrate that superfluidity can be achieved for flow above the critical velocity through quantum interference induced resonances. This has far reaching consequences for the fundamental understanding of superfluidity and superconductivity and opens up new application possibilities in quantum metrology, e.g. in rotation sensing.