Manifestation of a semimetallic state in cyclotron resonance in low-symmetry HgTe-based quantum wells
| Autor: | Dmitry Smirnov, Nikolay N. Mikhailov, G. Yu. Vasileva, Yu. B. Vasil'ev, A. A. Greshnov |
|---|---|
| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | JETP Letters. 97:102-106 |
| ISSN: | 1090-6487 0021-3640 |
| DOI: | 10.1134/s0021364013020069 |
| Popis: | Cyclotron-resonance measurements in 21-nm-thick HgTe/CdHgTe quantum wells of different crystallographic orientations have been performed. It has been found that, in contrast to the structures with the (001) orientation of the quantum-well plane, (013)-oriented quantum wells are semimetallic and their absorption spectra exhibit both electron and hole cyclotron-resonance lines. The simultaneous presence of the two types of charge carriers originates from an overlap between the upper heavy-hole quantum-confinement subbands hh1 and hh2. This overlap is caused by the strong interaction of these subbands with the Dyakonov-Khaetskii interface state. Calculations carried out using the eight-band kp-Hamiltonian indicate that, for known values of the band-structure parameters, the overlap between hh2 and hh1 subbands does not occur; this result is in agreement with the cyclotron-resonance data for (001)-oriented structures. The enhanced interaction between heavy-hole and interface states owing to the existence of steps at low-symmetry heterointerfaces may be the mechanism responsible for the appearance of an overlap between subbands in HgTe quantum wells with orientation different from (001). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|