Spin resonant optical four wave mixing in Pb1−xSnxTTe epitaxial layers and in Pb1−xSnx/PbTe superlattices

Spin resonances of the third-order non-linear susceptibility of epitaxial layers of n- and p-type Pb_1?xSn_xTe and Pb_1?xSn_xTe/PbTe superlatttices have been observed by four photon mixing of the radiation of two CO₂-lasers. Precise data on the effective g-values of the electrons and holes of Pb_1?xSn_xTe were obtained. These data and the results of magneto-optical interband absorption measurements are used to obtain k·p parameters within the Mitchell and Wallis band model. In the Pb_1?xSn_xTe/PbTe superlattices, the same g-values for electrons as in the Pb_1?xSn_xTe films with the same composition x are found. Consequently, the electrons in the superlattices are confined within the Pb_1?xSn_xTe layers. Therefore the Pb_1?xSn_xTe/PbTe system forms a type I and not a staggered superlattice.