Abstract
Spin properties of free charge carriers in PbTe and PbSe are analysed using for this purpose the concept of spin surface, which in the simplest case reduces to the Bloch sphere. It is shown that in lead chalcogenides the spin surfaces are ellipsoids, the principal axes of which depend on the charge carrier wave vector, spin–orbit interaction strength, and the basis functions used to construct the Hamiltonian. The present results may be useful in the study of dynamics of the polarized charge carriers injected electrically or optically into the volume of PbTe, PbSe or PbS.