Spin orbit interaction can be strongly boosted when a heavy element is embedded into an inversion asymmetric crystal field. A simple structure to realize this concept in a 2D crystal contains three atomic layers, a middle one built up from heavy elements generating strong atomic spin-orbit interaction and two neighboring atomic layers with different electron negativity. BiTeI is a promising candidate for such a 2D crystal, since it contains heavy Bi layer between Te and I layers. Recently the bulk form of BiTeI attracted considerable attention due to its giant Rashba interaction, however, 2D form of this crystal was not yet created. In this work we report the first exfoliation of single layer BiTeI using a recently developed exfoliation technique on stripped gold. Our combined scanning probe studies and first principles calculations show that SL BiTeI flakes with sizes of 100 μm were achieved which are stable at ambient conditions. The giant Rashba splitting and spin-momentum locking of this new member of 2D crystals open the way towards novel spintronic applications and synthetic topological heterostructures.
Cite
@article{arxiv.1709.09732,
title = {Exfoliation of single layer BiTeI flakes},
author = {Bálint Fülöp and Zoltán Tajkov and János Pető and Péter Kun and János Koltai and László Oroszlány and Endre Tóvári and Hiroshi Murakawa and Yoshinori Tokura and Sándor Bordács and Levente Tapasztó and Szabolcs Csonka},
journal= {arXiv preprint arXiv:1709.09732},
year = {2018}
}