Strong Coupling Correction in Superfluid $^3$He in Aerogel
Abstract
Effects of impurity scatterings on the strong coupling (SC) contribution, stabilizing the ABM (axial) pairing state, to the quartic term of the Ginzburg-Landau (GL) free energy of superfluid He are theoretically studied to examine recent observations suggestive of an anomalously small SC effect in superfluid He in aerogels. To study the SC corrections, two approaches are used. One is based on a perturbation in the short-range repulsive interaction, and the other is a phenomenological approach used previously for the bulk liquid by Sauls and Serene [Phys.Rev.B 24, 183 (1981)]. It is found that the impurity scattering favors the BW pairing state and shrinks the region of the ABM pairing state in the T-P phase diagram. In the phenomenological approach, the resulting shrinkage of the ABM region is especially substantial and, if assuming an anisotropy over a large scale in aerogel, leads to justifying the phase diagrams determined experimentally.
Cite
@article{arxiv.0707.0954,
title = {Strong Coupling Correction in Superfluid $^3$He in Aerogel},
author = {Kazushi Aoyama and Ryusuke Ikeda},
journal= {arXiv preprint arXiv:0707.0954},
year = {2009}
}
Comments
19 pages, 9 figures, Accepted for publication in Phys. Rev. B