Effects of Exchange and Correlations on Liquid 3 He in Aerogel
J. A. Sauls
Department of Physics and Astronomy, Northwestern University, Evanston IL 60208 USA
Superfluid 3 He confined in silica aerogel provides a unique system for studying the effects of quenched
disorder, spatial confinement and structural correlations of the scattering medium on the ordered phases
of an unconventional superfluid. In zero field a gapless Balian-Werthamer phase is stabilized at pressures
up to the solidification pressure for aerogels with porosity of ≈ 98%, while superfluidity is suppressed
below a critical pressure of pc ≈ 6 bar. New properties of liquid 3 He may be realized in a magnetic
field due to the indirect exchange interaction between solid 3 He atoms plating the strands and 3 He
quasiparticles. I present theoretical results for the B-T phase diagram and spin transport arising from
the indirect exchange coupling. New phases of superfluid 3 He may also be realized in aerogels that provide
anisotropic scattering of quasiparticles via either long- or short-range strand-strand correlations. Longrange anisotropy may be induced by the application of uniaxial stress to the aerogel. Phase diagrams for
these classes of aerogels are presented.
Sorting category: Ac Quantum gases, fluids and solids
Keywords: Superfluidity, 3 He-Aerogel, Disorder, Confinement, Broken Symmetry
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