A New Electromagnetic Mode in Cu

Abstract

For a thin slab of Cu with a static magnetic field applied normal to the slab and approximately along the [110], we have studied the circularly polarized transmission of electromagnetic waves in the 1.0 MHz range. We find that the previously reported oscillations propagating in the Doppler shifted cyclotron resonance (DSCR) absorption region have a polarization sense opposite to that of the helicon and we interpret these as a mode associated with the DSCR. We have computed the dispersion using an approximate copper Fermi surface and find agreement with the experimental dispersion and attenuation. The mode is similar in origin to that predicted for a model Fermi surface with electrons which drift along the field with a constant displacement per cyclotron period.