Inversion asymmetry and magneto-optical selection rules inn-type zinc-blende semiconductors

Far-infrared studies of magnetotransmission in n-type InSb, carried out in the parallel Voigt configuration, reveal an unusual dependence of the spin-resonance absorption on the orientation of the applied field B${\to }_0$ and on the direction of propagation q→ of the incident radiation with respect to the crystallographic axes. It was found that reversal of B${\to }_0$ leaving q→ fixed altered the intensity of the electric-dipole spin resonance. This result can be understood as an interference between electric-dipole and magnetic-dipole interactions when the former become allowed by virtue of mixing of Landau and Zeeman levels by a spin-orbit interaction lacking inversion symmetry. A theoretical study of this phenomenon is presented together with selection rules for magnetoabsorption in the parallel and perpendicular Voigt configurations as well as in the Faraday geometry. The results can be used to determine the inversion asymmetry parameter characterizing the spin-orbit interaction in connection with far-infrared experimental data.