Random anisotropy disorder in superfluid 3He-A in aerogel

TL;DR

This paper investigates the effects of random anisotropy disorder on superfluid 3He-A in aerogel, identifying different regimes with distinct NMR properties and linking them to known theoretical states.

Contribution

It clarifies the nature of orientational disorder regimes in superfluid 3He-A in aerogel, connecting experimental NMR observations to theoretical models of disorder and topological defects.

Findings

Identification of the (s)-state as the pure Larkin-Imry-Ma state

Proposal that the (f)-state involves topological defect contamination

Different NMR signatures for the two disorder regimes

Abstract

The anisotropic superfluid 3He-A in aerogel provides an interesting example of a system with continuous symmetry in the presence of random anisotropy disorder. Recent NMR experiments allow us to discuss two regimes of the orientational disorder, which have different NMR properties. One of them, the (s)-state, is identified as the pure Larkin-Imry-Ma state. The structure of another state, the (f)-state, is not very clear: probably it is the Larkin-Imry-Ma state contaminated by the network of the topological defects pinned by aerogel.