Intraband radiation absorption by free holes in GaAs/InGaAs quantum wells with taking into account non-sphericity of $kP$ hamiltonian

The system of Kane equations is derived and solved with taking into account the elastic stresses and the nonsphericity of the $kP$ Hamiltonian. Analytical expressions for the energy spectra of charge carriers are obtained. The radiation absorption coefficient by heavy holes with transition to the spin-split zone in GaAs/InGaAs quantum wells was calculated for different directions of polarization of the incident radiation. It was shown that for the GaAs/InGaAs heterostructure, the maximum absorption will be observed when the QW width is 4–6 nm.