Interband Magnetoreflection and Band Structure of HgTe

Magnetoreflection associated with ${\Gamma }_6\to {\Gamma }_8$ and ${\Gamma }_8\to {\Gamma }_8$ interband transitions has been observed. The data provide strong evidence that HgTe has the inverted band structure of gray tin. By fitting the ${\Gamma }_6\to {\Gamma }_8$ transitions to the coupled ${\Gamma }_6-{\Gamma }_7-{\Gamma }_8$ theory it is found that $E_g=-0.283\mathrm{}\pm 0.001$ eV and $E_p=18\mathrm{}\pm 1$ eV, where the errors reflect the uncertainties of the higher-band parameters. These values are in reasonable agreement with data from conduction-band effective-mass determinations. Some results of Shubnikov-de Haas measurements on $n$-type HgTe are presented and compared with the magnetoreflection band parameters.