Anomalous Landé factor in narrow-gap semiconductor heterostructures

In the frame of a full 8×8 k.p Hamiltonian, an exhaustive study of magneto-optical properties of narrow-gap semiconductor heterostructures has been developed. The effects of spatial confinement on the conduction Landau ladders of Hg1−xCdxTe/CdTe quantum wells are described. We report anomalous spin crossings of the Landau fan plots which lead to a sign inversion of the effective Landé factor as the magnetic field strength increases. Our quantitative explanation shows that the analyzed effects appear to be very sensitive to the temperature and the Cd-concentration of the sample. We discuss how the complemental aspect of the absorption coefficient obtained within Faraday and Voigt configurations may allow a direct evaluation of the anomaly in the g-factor as a function of the field.