Experiments with $^{3}$He in 10{\%} uniaxially compressed aerogel: the superfluid phase diagram

ORAL

Abstract

Entraining $^{3}$He in aerogel provides a way to introduce disorder in the otherwise ideal quantum fluid. Motivated by the recent prediction that uniaxially compressed aerogel can stabilize the anisotropic A phase over the isotropic B phase, we use a torsional oscillator technique to measure the superfluid phase diagram of $^{3}$He entrained in 10{\%} axially compressed, 98{\%} porous aerogel. We observe that a broad region of the temperature-pressure phase diagram is occupied by the metastable A phase. The reappearance of the A phase on warming from the B phase, before superfluidity is extinguished at T$_{c}$, is in contrast to its absence in uncompressed aerogel. We also find that the anticipated alignment of the angular momentum vector by compression is not observed.

Authors

  • Nikolay Zhelev

    Cornell University

  • Robert Bennett

    Cornell University

  • Eric Smith

    Cornell University

  • Johannes Pollanen

    Northwestern University

  • William Halperin

    Northwestern University

  • Jeevak Parpia

    Cornell University