Zeeman-Type Magneto-Optical Studies of Interband Transitions in Semiconductors

Abstract

In the presence of a magnetic field the quasi-continous levels of simple energy bands are coalesced into one-dimensional sub-bands and the "time reversal" degeneracy of the levels is split. The energy levels are characterized by the quantum numbers: $\ensuremath{\hbar}{k}_{H}$, the crystal momentum along the magnetic field direction; $l$, the Landau magnetic quantum number; and $M$, the component of the total angular momentum along the magnetic field which is characteristic of the atomic states in the tight-binding limit. In the case of degenerate valence bands, the effect of a magnetic field is complicated by degeneracy effects and the levels in a magnetic field are characterized by two or more pairs of ($l, M$) values. The selection rules, polarization effects, and the character of the absorption spectra for interband transitions in the presence of a magnetic field are discussed and illustrated by experimental data for Ge and InSb. A discussion of practical and experimental considerations of Zeeman-type interband magneto-optical effects is also presented.