Dynamical indistinguishability and statistics in quantum fluids

TL;DR

This paper introduces a dynamical criterion for when quantum statistical effects become observable in quantum fluids, linking particle indistinguishability to a time-dependent transition that can be experimentally tested.

Contribution

It proposes a novel dynamical condition and quantitative criterion for the emergence of quantum statistics in fluids, extending understanding beyond static considerations.

Findings

Particle exchange effects depend on a characteristic time scale.

Quantum statistics activate at long times, not short times.

Experimental verification of the transition is feasible.

Abstract

For a system to qualify as a quantum fluid, quantum-statistical effects should operate in addition to quantum-mechanical ones. Here, we address the hitherto unexplored dynamical condition for the quantum-statistical effects to be manifested, and consider particle exchange events in the gaslike regime of fluid dynamics as a dynamical process with an intrinsic time scale. We subsequently propose a quantitative criterion of particle indistinguishability and associated quantum statistics to be inoperative at short time and emerge at long time. Verifiable experimentally, our predictions enable a systematic search for a transition between statistics-active and statistics-inactive regimes in quantum fluids.