Universal Behaviour of the Superfluid Fraction and Tc of He-3 in 99.5% Open Aerogel

TL;DR

This study investigates the superfluid transition of He-3 in a highly porous aerogel, revealing a universal relation between transition temperature suppression and superfluid density across different samples.

Contribution

It demonstrates a universal behavior of superfluid fraction and transition temperature suppression of He-3 in aerogel, bridging previous findings in different aerogel densities.

Findings

Superfluid transition temperature is suppressed in aerogel.

Superfluid density shows a similar suppression pattern.

Universal relation between suppression of Tc and superfluid density.

Abstract

We have investigated the superfluid transition of He-3 in a 99.5% porosity silica aerogel. This very dilute sample shows behaviour intermediary between bulk He-3 and He-3 confined to the denser aerogels previously studied. We present data on both the superfluid transition temperature and the superfluid density and compare our results with previous measurements. Finally, we show that the suppression of the superfluid transition temperature and suppression of the superfluid density of He-3 in aerogel follow a universal relation for a range of aerogel samples.