InterbandΓ6→Γ8Magnetoabsorption in HgTe

Magnetoabsorption associated with ${\Gamma }_6\to {\Gamma }_8$ transitions was investigated at 4.4 °K, on pure $n$-type HgTe thin crystals in the spectral region 300-400 meV for $\sigma$ and $\pi$ polarizations. Analysis of experimental spectra is performed using both the three-band model (including the nonparabolicity), and the theory of Luttinger. Band parameters are determined by fitting transition energies: $E_{{\Gamma }_8}-E_{{\Gamma }_6}=302.5\mathrm{}$ meV, $\frac{m_{{\Gamma }_6}}{m_0}=0.028\mathrm{}\pm 0.001$, and $g_{{\Gamma }_6}=-41\mathrm{}\pm 4$ at $\Gamma$. ${\Gamma }_8$ Luttinger parameters (${\gamma }_1=-12.8,\overline{\gamma }=-8.4,\kappa =-10.5\mathrm{}$) satisfactorily explain interband and intraband ${\Gamma }_8$ magnetoabsorption. The structure of ${\Gamma }_8$ magnetic levels near $\Gamma$ is quantitatively described by calculating the $k_H$ dependence of the energies in the [111] direction. A complex structure is found for a set of heavy holes.