Anisotropic two-dimensional electron gas at SrTiO3(110)
- Author(s)
- Zhiming Wang, Zhicheng Zhong, Xianfeng Hao, Stefan Gerhold, Bernhard Stoeger, Michael Schmid, Jaime Sanchez-Barriga, Andrei Varykhalov, Cesare Franchini, Karsten Held, Ulrike Diebold
- Abstract
Two-dimensional electron gases (2DEGs) at oxide heterostructures are attracting considerable attention, as these might one day substitute conventional semiconductors at least for some functionalities. Here we present a minimal setup for such a 2DEG-the SrTiO3(110)-(4 x 1) surface, natively terminated with one monolayer of tetrahedrally coordinated titania. Oxygen vacancies induced by synchrotron radiation migrate underneath this overlayer; this leads to a confining potential and electron doping such that a 2DEG develops. Our angle-resolved photoemission spectroscopy and theoretical results show that confinement along (110) is strikingly different from the (001) crystal orientation. In particular, the quantized subbands show a surprising "semiheavy" band, in contrast with the analog in the bulk, and a high electronic anisotropy. This anisotropy and even the effective mass of the (110) 2DEG is tunable by doping, offering a high flexibility to engineer the properties of this system.
- Organisation(s)
- Computational Materials Physics
- External organisation(s)
- Technische Universität Wien, Helmholtz-Zentrum Berlin für Materialien und Energie
- Journal
- Proceedings of the National Academy of Sciences of the United States of America (PNAS)
- Volume
- 111
- Pages
- 3933-3937
- No. of pages
- 5
- ISSN
- 0027-8424
- DOI
- https://doi.org/10.1073/pnas.1318304111
- Publication date
- 03-2014
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103025 Quantum mechanics, 103036 Theoretical physics, 103015 Condensed matter, 103009 Solid state physics
- Keywords
- ASJC Scopus subject areas
- General
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/71fc3f6a-fdae-4a07-9bc9-aa36f222ad61