The voigt-type magneto-kerr effect in cubic semiconductors having ellipsoidal constant energy surfaces

Abstract

A plane-wave analysis is given for the Voigt orientation of an applied static magnetic field − B in cubic semiconductors having ellipsoidal constant energy surfaces. The effect is shown to be highly anisotropic with respect to the orientation of − B (magneto-anisotropy) as well as to the initial polarization direction of the incident wave with respect to − B (polarization anisotropy). The character and extent of the magneto-anisotropy depends not only on the location of the energy extrema, but on the anisotropy of the energy surfaces and on the energy dependence and anisotropy of the scattering processes. Calculations are given for the cases of propagation along 〈100〉 and 〈110〉 crystallographic directions in n-type germanium. High-field effects and infrared (IR) behavior are considered; however, the low-field quadratic range for microwaves in high-loss material is emphasized. A useful approximation for the high-loss case is given. Particular attention is given to the potential diagnostic applications of the effect. Room-temperature measurements of the Voigt-type Kerr effect for the TE 11 circular-waveguide mode at 35 GHz in n-type Ge are presented and compared with plane-wave calculations for propagation along 〈100〉 and 〈110〉 directions. Good quantitative agreement is obtained when the plane-wave calculations are reduced by the same mode-reduction factor as is applicable for the Faraday orientation.