Calculation of Helicon Propagation and Gantmakher-Kaner Oscillations in Copper

The transmission of electromagnetic fields through thin copper slabs with the magnetic field →B₀ and the propagation vector →q along the [001] and [111] directions has been investigated numerically and the results compared with experimental results of Wood and Gavenda. The conductivity tensor used in the calculations is derived from a model Fermi surface proposed by Halse. Only the variation of the area A enclosed by the charge carriers and the derivatives of the area with respect to kz, ∂A∂kz are considered. For →B₀∥[001], the calculated and experimental values of the helicon edge differ less than 3% for the frequencies studied. The electrons responsible for the helicon edge are associated with a value 9.5 ×{} 10⁸ cm^-1 for |∂A∂kz|. A discussion of the relative damping effects by the charge carriers is given. For →B₀∥[111]. Gantmakher-Kaner (GK) oscillations with a period of 590 G are observed in both the calculated and experimental results. The amplitude modulation of the GK oscillations leads to an interpretation in terms of a beating of two separate sets of GK oscillations, one set associated with maximum in |∂A∂kz| and the other set associated with a minimum in |∂A∂kz|