Riepl, Josef and Aichner, M. and Mikhailov, N. N. and Dvoretsky, S. A. and Budkin, G. and Ganichev, Sergey D. and Lange, C. and Mornhinweg, Joshua and Huber, R. (2025) All-optical band structure reconstruction and onset of Landau quantization of Dirac fermions. APPLIED PHYSICS LETTERS, 127 (10): 103102. ISSN 0003-6951, 1077-3118
Full text not available from this repository. (Request a copy)Abstract
The nature of relativistic electrons in solids depends on the precise shape of the underlying band structure. Prominently, symmetry-related mechanisms, such as the breaking of time-reversal symmetry in topological insulators, can lead to the emergence of bandgaps on small energy scales. It is, thus, important to quantify potential gaps of the Dirac cone with meV precision. Yet, established band structure measurements are often challenged by their strict surface sensitivity or limited energy resolution. In this work, we use broadband, time-resolved THz magneto-spectroscopy to access the band structure of Dirac electrons in a buried HgTe quantum well by contact-free, all-optical measurements. Optical doping allows us to control the Fermi level without applying any electrical gate voltages. The background-free measurement of the cyclotron resonance of the Dirac system over 2.5 optical octaves, a broad range of magnetic field strengths, and different Fermi energies allows us to reconstruct the band structure near the Dirac point with sub-meV precision and to observe a crossover of Landau quantization from a quasi-classical to the relativistic regime.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | QUANTUM; INSULATOR |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Huber > Group Rupert Huber |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 21 Apr 2026 04:33 |
| Last Modified: | 21 Apr 2026 04:33 |
| URI: | https://pred.uni-regensburg.de/id/eprint/66884 |
Actions (login required)
 |
View Item |
