Equal-Spin Pairing State of Superfluid $^3$He in Aerogel

TL;DR

This paper theoretically investigates the equal-spin pairing (A-like phase) of superfluid helium-3 in aerogels using Ginzburg-Landau theory, revealing the ABM state as the most likely candidate for the observed phase.

Contribution

It provides a theoretical phase diagram for superfluid $^3$He in aerogels and identifies the ABM state as the best candidate for the A-like phase.

Findings

ABM state with quasi long-ranged order is favored

Strange lowering of the polycritical point (PCP) observed experimentally

Phase diagram mapped out in the Ginzburg-Landau region

Abstract

The equal-spin pairing (ESP) state, the so-called A-like phase, of superfluid $^3$He in aerogels is studied theoretically in the Ginzburg-Landau (GL) region by examining thermodynamics, and the resulting equilibrium phase diagram is mapped out. We find that, among the ABM, planar, and robust pairing states, the ABM state with presumably quasi long-ranged superfluid order is the best candidate of the A-like phase with a strange lowering of the polycritical point (PCP) observed experimentally.