Magnetization and Spin-Diffusion of Liquid 3He in Aerogel

TL;DR

This paper presents theoretical calculations and experimental comparisons of spin diffusion and magnetization in liquid 3He within aerogel, revealing the effects of scattering and correlations on superfluid properties.

Contribution

It introduces a comprehensive theoretical model including elastic and inelastic scattering, and correlation effects, to explain spin diffusion and magnetization data in 3He in aerogel.

Findings

Determined the elastic mean free path in aerogel.

Validated the theory with experimental magnetization data.

Showed correlation effects are crucial for consistent interpretation.

Abstract

We report theoretical calculations of the normal-state spin diffusion coefficient of 3He in aerogel, including both elastic and inelastic scattering of 3He quasiparticles, and compare these results with experimental data for 3He in 98% porous silica aerogel. This analysis provides a determination of the elastic mean free path within the aerogel. Measurements of the magnetization of the superfluid phase provide a test of the theory of pairbreaking and magnetic response of low-energy excitations in the ``dirty'' B-phase of 3He in aerogel. A consistent interpretation of the data for the spin-diffusion coefficient, magnetization and superfluid transition temperature is obtained by including correlation effects in the aerogel density.