We have made accurate measurements of the phase velocity in liquid 3He at 0.6 bar near Tc using a path length modulation technique. The frequency used in this measurement (113 MHz) is much higher than any of the collective mode frequencies and well above the threshold for pair-breaking, ω ≫ Δ and ω ≫ 2Δ0. We have observed a sharp but small linear increase in the phase velocity below Tc and a small decrease from the expected behavior in the normal fluid region very close to the transition temperature.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- Condensed Matter Physics