Sound Propagation in Normal and Superfluid 3He
We present measurements of the pressure dependence of the attenuation and velocity of sound in the hydrodynamic regime and in both the normal and superfluid zero sound regime of 3He. The velocity and attenuation were studied at a frequency of 20.24 MHz and at pressures of 17.00, 21.00, 21.50, 21.80, 22.00, 23.17, 26.00, and 28.00 bar in the zero sound regime. In the hydrodynamic region the temperature dependence of the attenuation was studied at 5.48 and 10.02 MHz and at pressures of 0.69, 1.38, and 2.76 bar. At a pressure of 29.3 bar and frequency of 20.24 MHz the transition from hydrodynamic to zero sound behavior was studied for both the velocity and attenuation. In addition, the anisotropy of the velocity and the attenuation as a function of the angle between the direction of an applied external magnetic field and the sound propagation direction was observed in the superfluid A phase at a pressure of 26.0 bar; no anisotropy was observed in the B phase at 21.0 bar. The observed behavior associated with a collective excitation of the order parameter in the B phase is shown to be qualitatively in agreement with theoretical predictions. At pressures slightly above the polycritical point some unexplained structure is observed in the velocity near the AB transition.
KeywordsQuartz Magnesium Anisotropy Attenuation Helium
Unable to display preview. Download preview PDF.
- (1).L. D. Landau, Zh. Eksp. Teor. Fiz. 32, 59 (1957), [Sov. Phys.-JETP 5 ,101 (1957)].Google Scholar
- (4).G. Baym and C. Pethick, “Landau Fermi Liquid Theory and Low Temperature Properties of Liquid 3He,” in The Physics of Liquid and Solid Helium, Vol. II, edited by K. H. Bennemann and J. B. Ketterson (John Wiley, N.Y.) to be published.Google Scholar
- (5).L. D. Landau and E. M. Lifshitz, Fluid Mechanics (Pergamon Press, Oxford, 1959).Google Scholar
- (20).J. W. Serene, “Theory of Collisionless Sound in Superfluid 3He,” Thesis, Cornell University (1974) and to be published.Google Scholar
- (20a).P. Wölfle, these proceedings, and to be published.Google Scholar
- (20b).K. Maki and H. Ebisawa, to be published.Google Scholar
- (21).We thank Dr. Serene for sending us his program for computing these quantities.Google Scholar
- (23).K. Miyano and J. B. Ketterson, Phys. Rev. to be published.Google Scholar
- (26).Paul D. Roach, B. M. Abraham, P. R. Roach, and J. B. Ketterson, to be published.Google Scholar
- (28).K. N. Zinovieva, Zh. Eksp. Teor. Fiz.34, 609 (1958); [Sov. Phys.-JETP 7 ,421 (1958)].Google Scholar
- (29).R. D. Taylor and J. G. Dash, Phys. Rev. 132, 2372 (1965).Google Scholar