We report the results of high-frequency acoustic shear impedance measurements on superfluid He3 confined in 98% porosity silica aerogel. Using 8.69MHz continuous wave excitation, we measured the acoustic shear impedance as a function of temperature for the sample pressures of 28.4 and 33.5bar. We observed the A-B transition on warming in zero magnetic field. Our observations show that the A and B phases in aerogel coexist in a temperature range of about 100μK in width. We propose that differences in the relative stability of the A and B phases arising from anisotropic scattering can account for our observations.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Sep 1 2005|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics