Vortex core transitions in superfluid 3He in globally anisotropic aerogels

TL;DR

This study investigates how uniaxial deformation of aerogels affects vortex core structures in superfluid 3He, revealing deformation-dependent vortex core transitions with potential experimental implications.

Contribution

It provides the first detailed numerical analysis of vortex core transitions in superfluid 3He within anisotropic aerogels, highlighting the influence of deformation type on vortex states.

Findings

Vortex core transitions depend on the type of uniaxial deformation.

Compressed aerogels show vortex core transitions in B-like phases at all pressures.

Stretched aerogels exhibit different vortex core transition behaviors in A-like and B-like phases.

Abstract

Core structures of a single vortex in A-like and B-like phases of superfluid 3He in uniaxially compressed and stretched aerogels are studied by numerically solving Ginzburg-Landau equations derived microscopically. It is found that, although any uniaxial deformation leads to a wider A-like phase with the axial pairing in the pressure-temperature phase diagram, the vortex core states in the two phases in aerogel depend highly on the type of deformation. In a compressed aerogel, the first-order vortex core transition (VCT) previously seen in the bulk B phase appears at any pressure in the B-like phase while no strange vortex core is expected in the corresponding A-like phase. By contrast, in a stretched aerogel, the VCT in the B-like phase is lost while another VCT is expected to occur between a nonunitary core and a polar one in the A-like phase. Experimental search for these results is hoped to understand correlation between superfluid 3He and aerogel structure.