Journal Article

Giant Magnetic Band Gap in the Rashba-Split Surface State of Vanadium-Doped BiTeI: A Combined Photoemission and Ab Initio Study

Tereshchenko, O. E., Otrokov, M. M., Rader, O., Varykhalov, A. Yu, Kokh, K. A., Golyashov, V. A., Sánchez-Barriga, J., Ernst, A., Rusinov, I. P., Shikin, A. M., Klimovskikh, I. I., Chulkov, E. V.

2017

Overview

One of the most promising platforms for spintronics and topological quantum computation is the two-dimensional electron gas (2DEG) with strong spin-orbit interaction and out-of-plane ferromagnetism. In proximity to an s -wave superconductor, such 2DEG may be driven into a topologically non-trivial superconducting phase, predicted to support zero-energy Majorana fermion modes. Using angle-resolved photoemission spectroscopy and ab initio calculations, we study the 2DEG at the surface of the vanadium-doped polar semiconductor with a giant Rashba-type splitting, BiTeI. We show that the vanadium-induced magnetization in the 2DEG breaks time-reversal symmetry, lifting Kramers degeneracy of the Rashba-split surface state at the Brillouin zone center via formation of a huge gap of about 90 meV. As a result, the constant energy contour inside the gap consists of only one circle with spin-momentum locking. These findings reveal a great potential of the magnetically-doped semiconductors with a giant Rashba-type splitting for realization of novel states of matter.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 119/118 / 140/146 / 639/301/119/544 / 639/301/119/997 / 639/766/119/2792 / 639/766/119/995 / High temperature / Humanities and Social Sciences / Magnetic fields / Magnetism / multidisciplinary / Phase transitions / Physics / Point defects / Science / Science (multidisciplinary) / Spectroscopy / Spectrum analysis / Splitting / Symmetry / Vanadium