Effective Mass and g-Factor of Two-Dimentional HgTe [GAMMA].sub.8-Band Electrons: Shubnikov-de Haas Oscillations

We present a study of Shubnikov-de Haas (SdH) oscillations at temperatures of (2.2-10) K in magnetic fields up to 2.5 T in the HgCdTe/HgTe/HgCdTe heterostructure for a wide (20.3 nm) HgTe quantum well with an inverted energy band structure. The analysis of the temperature dependence of SdH amplitude in weak fields, in a region of doubly degenerate magnetoresistance peaks, led us to the value of effective electron mass m.sub.c/m.sub.0 = (0.022 ± 0.002) which is about half the theoretical estimates. But in a region of higher magnetic fields, for nondegenerate magnetoresistance peaks, we confidently have m.sub.c/m.sub.0 = (0.034 ± 0.003) in good agreement both with the theoretical estimation and with our experimental results on the analysis of activation transport under quantum Hall effect regime. The reasons for this discrepancy are discussed.