Superfluid Phases of 3He in Aerogel

TL;DR

This paper develops a phenomenological criterion to identify possible order parameters for superfluid phases of 3He in aerogel, proposing candidates for the observed A-like phase and analyzing magnetic field effects.

Contribution

It introduces a criterion for selecting order parameters of superfluid 3He in aerogel and proposes ESP-type candidates for the A-like phase.

Findings

Bulk B-phase order parameter meets the criterion.

Bulk A-phase order parameter does not meet the criterion.

Proposed ESP-type order parameters as candidates for A-like phase.

Abstract

Within a phenomenological approach a criterion for a choice of forms of the order parameter of the superfluid phases of 3He in aerogel in a vicinity of the transition temperature is derived. The order parameter of bulk B-phase of 3He meets this criterion and that of the bulk A-phase doesn`t. A class of order parameters of Equal Spin Pairing (ESP) type meeting the derived criterion is discussed. Order parameters belonging to this class are proposed as candidates for the observed A-like superfluid phase of liquid 3He in aerogel. Effect of magnetic field on the order parameters of this class is considered.