title: Enhanced infrared magneto-optical response of the nonmagnetic semiconductor BiTeI driven by bulk Rashba splitting.
abstract: We study the magneto-optical (MO) response of the polar semiconductor BiTeI with giant bulk Rashba spin splitting at various carrier densities. Despite being nonmagnetic, the material is found to yield a huge MO activity in the infrared region under moderate magnetic fields (up to 3 T). Our first-principles calculations show that the enhanced MO response of BiTeI comes mainly from the intraband transitions between the Rashba-split bulk conduction bands. These transitions connecting electronic states with opposite spin directions become active due to the presence of strong spin-orbit interaction and give rise to distinct features in the MO spectra with a systematic doping dependence. We predict an even more pronounced enhancement in the low-energy MO response and dc Hall effect near the crossing (Dirac) point of the conduction bands.
authors.affiliation: Multiferroics Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), c/o Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: L
authors.initials: L
authors.lastname: Demkó
authors.forename: G A H
authors.initials: GA
authors.lastname: Schober
authors.forename: V
authors.initials: V
authors.lastname: Kocsis
authors.forename: M S
authors.initials: MS
authors.lastname: Bahramy
authors.forename: H
authors.initials: H
authors.lastname: Murakawa
authors.forename: J S
authors.initials: JS
authors.lastname: Lee
authors.forename: I
authors.initials: I
authors.lastname: Kézsmárki
authors.forename: R
authors.initials: R
authors.lastname: Arita
authors.forename: N
authors.initials: N
authors.lastname: Nagaosa
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura