Cyclotron resonance line shape and cyclotron waves for a spherical Fermi surface

Abstract

A recently developed formalism is applied to the evaluation of the surface impedance for a metal in a magnetic field. A spherical Fermi surface is assumed for the metal and the field configuration considered is the Azbel-Kaner geometry. The formalism makes use of the dispersion relation for extraordinary cyclotron waves in an essential way and the authors therefore give a detailed treatment of this dispersion relation for a finite value of omega tau and for frequencies of the order of 25-50 GHz. The fundamental cyclotron resonance and the surface impedance anomalies, occurring above the fundamental resonance, observed experimentally in potassium by Dunifer and co-workers are calculated. The correlation between the surface impedance and the dispersion relation for the cyclotron waves is pointed out and the significance of the polarisation properties of the waves is emphasised.