ZERO SOUND END QUASIWAVE - SEPARATION IN THE MAGNETIC-FIELD

Theoretical and experimental results on the behavior of the longitudin al and transverse Electron sound in a weak magnetic field are presente d. It is shown theoretically that the effects of the magnetic field on zero sound velocity and ballistic transfer are opposite in sign and h ave sufficiently different dependences on the sample width, excitation frequency and relaxation time. This permits us to separate experiment ally the Fermi-liquid and ballistic contributions in the electron soun d signals. For the first time the ballistic transfer of the acoustic e xcitation by the quasiwave has been observed in zero magnetic field.