Hydrodynamic Attractor in Ultracold Atoms

TL;DR

This paper proposes using ultracold atomic gases with driven scattering lengths to observe hydrodynamic attractors, providing a new experimental platform to study universal equilibration behaviors in quantum fluids.

Contribution

It introduces a novel method to observe hydrodynamic attractors in ultracold atoms via scattering length manipulation, with explicit models and analytical solutions.

Findings

Derived a hydrodynamic relaxation model for driven ultracold gases

Analytically solved the dynamics revealing the hydrodynamic attractor

Proposed a feasible experimental setup for observing attractors

Abstract

The hydrodynamic attractor is a concept that describes universal equilibration behavior in which systems lose microscopic details before hydrodynamics becomes applicable. We propose a setup to observe hydrodynamic attractors in ultracold atomic gases, taking advantage of the fact that driving the two-body $s$-wave scattering length causes phenomena equivalent to isotropic fluid expansions. We specifically consider two-component fermions with contact interactions in three dimensions and discuss their dynamics under a power-law drive of the scattering length in a uniform system. By explicit computation, we derive a hydrodynamic relaxation model. We analytically solve their dynamics and find the hydrodynamic attractor solution. Our proposed method using the scattering length drive is applicable to a wide range of ultracold atomic systems, and our results establish these as a new platform for exploring hydrodynamic attractors.