1. Band Structure Near the Dirac Point in HgTe Quantum Wells with Critical Thickness
- Author
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Alexey Shuvaev, Vlad Dziom, Jan Gospodarič, Elena G. Novik, Alena A. Dobretsova, Nikolay N. Mikhailov, Ze Don Kvon, and Andrei Pimenov
- Subjects
Dirac fermions ,topological insulators ,band structure ,quantum wells ,cyclotron resonance ,Chemistry ,QD1-999 - Abstract
Mercury telluride (HgTe) thin films with a critical thickness of 6.5 nm are predicted to possess a gapless Dirac-like band structure. We report a comprehensive study on gated and optically doped samples by magnetooptical spectroscopy in the THz range. The quasi-classical analysis of the cyclotron resonance allowed the mapping of the band dispersion of Dirac charge carriers in a broad range of electron and hole doping. A smooth transition through the charge neutrality point between Dirac holes and electrons was observed. An additional peak coming from a second type of holes with an almost density-independent mass of around 0.04m0 was detected in the hole-doping range and attributed to an asymmetric spin splitting of the Dirac cone. Spectroscopic evidence for disorder-induced band energy fluctuations could not be detected in present cyclotron resonance experiments.
- Published
- 2022
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