Interband Magneto-Absorption and Faraday Rotation in InSb

Abstract

Direct interband magneto-optical transitions have been observed in pure $n$-type InSb at liquid-helium temperature using magnetic fields up to 96.5 kG. The theory of the magnetic levels in the valence and conduction bands at the zone center is carried out using a modification of the method of Luttinger and Kohn. The interaction between conduction and valence bands has been treated exactly, and the effect of higher bands to order ${k}^{2}$. Selection rules have been evaluated for both allowed ($\ensuremath{\Delta}n=0, \ensuremath{-}2$) and warping-induced ($\ensuremath{\Delta}n=2, \ifmmode\pm\else\textpm\fi{}4, \ensuremath{-}6$) direct valence-to-conduction-band transitions. Comparison of theoretical with experimental spectra (using circular and plane-polarized light in the Faraday and Voigt configurations, respectively) has shown good agreement for the magnetic field in the [110] and [100] crystal directions. The following band parameters are obtained: conduction-band effective mass ${m}_{\mathrm{c}}=0.0145{m}_{0}$: light-hole effective mass ${m}_{l.\mathrm{h}.}=0.0160{m}_{0}$; heavy-hole effective masses ${m}_{\mathrm{h}.\mathrm{h}.}[100]=0.32{m}_{0}$, ${m}_{\mathrm{h}.\mathrm{h}.}[110]=0.42{m}_{0}$, ${m}_{\mathrm{h}.\mathrm{h}.}[111]=0.44{m}_{0}$.