Limits of validity of the Rashba model in BiTeI: High-field magneto-optical study
Abstract
It was recently shown that BiTeI, a semiconductor with polar crystal structure, possesses a giant spin splitting of electrons, which has been interpreted in terms of Rashba-type spin-orbit coupling. Here we use high field magneto-optical spectroscopy to quantify the deviations of the conduction-band profile from this appealing, but at the same time, strongly simplifying model. We find that the optical response—comprising a series of inter-Landau level excitations—can be described by the Rashba model only at low magnetic fields. In contrast, the high-field response appears to be more consistent with a simple picture of massless electrons in a conical band. This points towards more linear rather than parabolic dispersion at energies well above the bottom of the conduction band.
- Publication:
-
Physical Review B
- Pub Date:
- October 2019
- DOI:
- 10.1103/PhysRevB.100.155203
- arXiv:
- arXiv:1907.06339
- Bibcode:
- 2019PhRvB.100o5203B
- Keywords:
-
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- 4 pages, 3 figures