Linear NMR in the polar phase of $^3$He in aerogel

TL;DR

This paper investigates the behavior of linear NMR signals in the polar phase of superfluid helium-3 confined in aerogel, focusing on uniform textures and the effects of half-quantum vortices.

Contribution

It provides the first theoretical and numerical analysis of linear NMR in the polar phase of helium-3, including vortex effects.

Findings

NMR response varies with vortex presence

Distinct signatures for uniform and vortex textures

Enhanced understanding of topological defects in superfluid helium-3

Abstract

$^3$He is an example of the system with non-trivial Cooper paring. A few different superfluid phases are known in this system. Recently the new one, the polar phase, have been observed in $^3$He confined in nematically ordered aerogel. A number of various topological defects including half-quantum vortices can exist the polar phase. In this work we present theoretical and numerical studies of linear NMR in the polar phase both in the uniform order-parameter texture and in the presence of half-quantum vortices.