Superfluid Quantum Criticality in Liquid 3He in Anisotropic Aerogel

TL;DR

This paper investigates the quantum critical behavior of superfluid phases in liquid 3He within anisotropic aerogels, revealing unique fluctuation dynamics and a weak divergence in compressibility near the critical pressure.

Contribution

It demonstrates the impact of anisotropic impurity scattering and line nodes on quantum fluctuations and critical phenomena in superfluid 3He.

Findings

Quantum fluctuations are influenced by impurity scattering and line nodes.

A weak divergence of compressibility appears near the critical pressure.

Distinct quantum critical behavior differs from isotropic aerogel cases.

Abstract

In the novel superfluid polar phase realized in liquid 3He in highly anisotropic aerogels, a quantum transition to the polar-distorted A (PdA) phase may occur at a low but finite pressure Pc(0). It is shown that a nontrivial quantum dynamics of the critical fluctuation of the PdA order is induced by the presence of both the columnar-like impurity scattering leading to the Anderson's Theorem for the polar phase and the line node of the quasiparticle gap in the state, and that, in contrast to the situation of the normal to the B phase transition in isotropic aerogels, a weakly divergent behavior of the compressibility appears in the quantum critical region close to Pc(0).