Cyclotron resonance in HgCdTe-based heterostructures in strong magnetic fields.

Cyclotron resonance (CR) study of HgCdTe-based quantum wells with both inverted and normal band structures in quantizing magnetic fields was performed. In normal-band sample in addition to electron CR transitions a strong absorption line presumably related to impurity transitions was discovered. Anticrossing of electron and hole Landau levels was observed in inverted-band sample. In semimetallic HgTe quantum wells with inverted band structure, a hole CR line was observed for the first The obtained results were interpreted within the Kane 8 × 8 model, the valence band offset of CdTe and HgTe, and the Kane parameter EP being adjusted

Magnetospectroscopy of 2D HgTe Based Topological Insulators

We report on a magnetospectroscopy study of a set of four HgTe quantum wells of different thickness. In quantizing magnetic fields, intraband and interband transitions have been observed. The obtained results are compared with the allowed transition energies calculated using the 8 × 8 Kane model

Experimental Observation of Temperature-Driven Topological Phase Transition in HgTe/CdHgTe Quantum Wells

We report on the comparison between temperature-dependent magneto-absorption and magnetotransport spectroscopy of HgTe/CdHgTe quantum wells in terms of the detection of the phase transition between the topological insulator and band insulator states. Our results demonstrate that temperature-dependent magnetospectroscopy is a powerful tool to discriminate trivial and topological insulator phases, yet the magnetotransport method is shown to have advantages for the clear manifestation of the phase transition with accurate quantitative values of the transition parameter (i.e., critical magnetic field Bc)