Scharf, Benedikt and Matos-Abiague, Alex and Zutic, Igor and Fabian, Jaroslav (2015) Probing topological transitions in HgTe/CdTe quantum wells by magneto-optical measurements. PHYSICAL REVIEW B, 91 (23): 235433. ISSN 2469-9950, 2469-9969
Full text not available from this repository.Abstract
In two-dimensional topological insulators, such as inverted HgTe/CdTe quantum wells, helical quantum spin Hall (QSH) states persist even at finite magnetic fields below a critical magnetic field B-c, above which only quantum Hall (QH) states can be found. Using linear-response theory, we theoretically investigate the magneto-optical properties of inverted HgTe/CdTe quantum wells, both for infinite two-dimensional and finite-strip geometries and for possible signatures of the transition between the QSH and QH regimes. In the absorption spectrum, several peaks arise due to nonequidistant Landau levels in both regimes. However, in the QSH regime, we find an additional absorption peak at low energies in the finite-strip geometry. This peak arises due to the presence of edge states in this geometry and persists for any Fermi level in the QSH regime, while in the QH regime the peak vanishes if the Fermi level is situated in the bulk gap. Thus, by sweeping the gate voltage, it is possible to experimentally distinguish between the QSH and QH regimes due to this signature. Moreover, we investigate the effect of spin-orbit coupling and finite temperature on this measurement scheme.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | HGTE; INSULATORS; TRANSPORT; ELECTRONS; SURFACE; SEMICONDUCTOR; SPINTRONICS; CONDUCTION; CONTACT; BI2SE3; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Chair Professor Richter > Group Jaroslav Fabian |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 10 Jul 2019 13:51 |
| Last Modified: | 10 Jul 2019 13:51 |
| URI: | https://pred.uni-regensburg.de/id/eprint/5309 |
Actions (login required)
 |
View Item |
