HIGH-FREQUENCY TRANSPORT OF ELECTRONS ON HELIUM FILMS

We have measured the microwave absorption of two-dimensional electrons on films of helium as a function of a perpendicular magnetic field B for different electron densities and at several clamping fields. The magnetic field dependent absorption increases linearly with the charge density as would be expected by the Drude theory. The absorption as a function of the magnetic field shows a maximum at 0.17 T. For higher fields it drops strongly and seems to have a logarithmic behavior which cannot yet be explained satisfactorily. From the position of the maximum we have estimated a dimple radius. © 1990.