Anomalies on the Zeeman splitting and dielectric response due to the lack of inversion symmetry in narrow-gap semiconductor quantum wells

An exhaustive study of magneto-optical properties in Hg_1-x Cd_xTe/CdTe quantum-wells has been developed. The strong interband mixing plays an essential role in defining the shape and the behavior of the dielectric response in this system, allowing for the appearance of spin-flip like excitations. Anomalous crossings of the Landau levels fan in narrow-gap semiconductor heterostructures and a peculiar sign inversion of the effective Lande g-factor as a function of the magnetic field are also predicted in this study. A quantitative evaluation shows that the analyzed effects are very sensitive to the temperature and to the Cd-concentration of the sample