Phase Stability of Superfluid $^{3}\mathrm{He}$ in Anisotropic Aerogel

TL;DR

This paper investigates how anisotropic disorder in silica aerogel influences the phase stability and orientation of superfluid helium-3's A and B phases, using a temperature-dependent anisotropic Ginzburg-Landau model.

Contribution

It introduces a model explaining the spontaneous reorientation of order parameter degrees of freedom in superfluid helium-3 within anisotropic aerogel.

Findings

Reorientation occurs at a field-independent transition temperature Tx.

The anisotropic Ginzburg-Landau model accounts for the observed phase behavior.

Anisotropic disorder influences the stability and orientation of superfluid phases.

Abstract

The A and B phases of superfluid 3 He have vector degrees of freedom that reflect their characteristic broken symmetries, respectively chiral and spin-orbit rotation axes. Anisotropic disorder in the superfluid, imbibed in uniformly strained silica aerogel, orients these degrees of freedom, thereby affecting phase stability. These degrees of freedom have been found to spontaneously reorient at a field-independent transition temperature Tx , that can be accounted for with a temperature dependent anisotropic Ginzburg-Landau model.