Phase diagram of the A and B phases of superfluid 3He in aerogel.
We report the first measurements of the A-B phase transition of superfluid 3He confined within 98% silica aerogel in high magnetic fields and low temperatures. A disk of aerogel is attached to a vibrating wire resonator. The resonant frequency yields a measure of the superfluid fraction rho(s)/rho of the 3He within the aerogel. The inferred rho(s)/rho value increases substantially at the A-to- B transition of the confined superfluid, allowing us to map the A-B phase diagram as a function of field and temperature. At 4.8 bars, the B-T transition curve looks very similar to that in bulk with a simple reduction factor of order 0.45 for both transition field and temperature.
Brussaard
P
P
Department of Physics, Lancaster University, Lancaster, LA1 4YB United Kingdom.
Fisher
S N
SN
Guénault
A M
AM
Hale
A J
AJ
Mulders
N
N
Pickett
G R
GR