Anomalous Lande factor in narrow-gap semiconductor heterostructures

In the frame of a full 8 x 8 k.p Hamiltonian, an exhaustive study of magnet o-optical properties of narrow-gap semiconductor heterostructures has been developed. The effects of spatial confinement on the conduction Landau ladd ers of Hg1-xCdxTe/CdTe quantum wells are described. We report anomalous spi n crossings of the Landau fan plots which lead to a sign inversion of the e ffective Lande factor as the magnetic field strength increases. Our quantit ative explanation shows that the analyzed effects appear to be very sensiti ve to the temperature and the Cd-concentration of the sample. We discuss ho w the complemental aspect of the absorption coefficient obtained within Far aday and Voigt configurations may allow a direct evaluation of the anomaly in the g-factor as a function of the field. (C) 2000 Elsevier Science Ltd. All rights reserved.