title: Sound propagation in coexistent Bose and Fermi superfluids in aerogel.
abstract: We report the first observation of longitudinal sound propagation in three dimensionally distributed Bose and Fermi superfluids in an acoustic investigation of phase separated 3He-4He mixtures confined to aerogel. At mK temperatures, this inhomogeneous system exhibits simultaneous 3He and 4He superfluidity leading to two "slow modes" along with the conventional sound mode. We also infer the superfluidity of isolated bubbles of pure 3He in a large 4He concentration sample.
authors.affiliation: Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York, USA.
authors.forename: G
authors.initials: G
authors.lastname: Lawes
authors.forename: A I
authors.initials: AI
authors.lastname: Golov
authors.forename: E
authors.initials: E
authors.lastname: Nazaretski
authors.forename: N
authors.initials: N
authors.lastname: Mulders
authors.forename: J M
authors.initials: JM
authors.lastname: Parpia