On the magnetic field dependence of acoustic wave velocity in the mixed state of a high- Tc superconductor

Abstract

The variation of the acoustic wave velocity with applied magnetic field in the mixed state of a high- T c superconductor is studied theoretically on the basis of a phenomenological model in which the coupling between the flux line lattice and the crystal lattice via the pinning potential is taken into account in a consistent manner. The theory gives good agreement with the recent results of Dolgopolov et al. in YBaCuO obtained experimentally using electromagnetically excited sound waves. The frequency dependence of the fractional change in acoustic velocity is also accounted for.