Control of a two-dimensional electron gas on SrTiO3 (111) by atomic oxygen

We report on the formation of a two-dimensional electron gas (2DEG) at the bare surface of (111) oriented SrTiO3. Angle resolved photoemission experiments reveal highly itinerant carriers with a sixfold symmetric Fermi surface and strongly anisotropic effective masses. The electronic structure of the 2DEG is in good agreement with self-consistent tight-binding supercell calculations that incorporate a confinement potential due to surface band bending. We further demonstrate that alternate exposure of the surface to ultraviolet light and atomic oxygen allows tuning of the carrier density and the complete suppression of the 2DEG.

Citation

McKeown Walker , S , De La Torre , A , Bruno , F Y , Tamai , A , Kim , T K , Hoesch , M , Shi , M , Bahramy , M S , King , P D C & Baumberger , F 2014 , ' Control of a two-dimensional electron gas on SrTiO 3 (111) by atomic oxygen ' , Physical Review Letters , vol. 113 , no. 17 , 177601 . https://doi.org/10.1103/PhysRevLett.113.177601

Publication

Physical Review Letters

Status

Peer reviewed

DOI

https://doi.org/10.1103/PhysRevLett.113.177601

ISSN

0031-9007

Type

Journal article

Rights

© 2014 American Physical Society. Reproduced in accordance with APS transfer of copyright agreement. The final version can also be found via the publisher's website: http://dx.doi.org/10.1103/PhysRevLett.113.177601

Description

This work was supported by Swiss National Science Foundation (200021-146995). P. D. C. K. was supported by the UK-EPSRC and the Royal Society and M. S. B. by Grant-in-Aid for Scientific Research (S) (No. 24224009) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.