title: Carrier-Density Control of the SrTiO3 (001) Surface 2D Electron Gas studied by ARPES.
abstract: The origin of the 2D electron gas (2DEG)stabilized at the bare surface of SrTiO3 (001) is investigated. Using high-resolution angle-resolved photoemission and core-level spectroscopy, it is shown conclusively that this 2DEG arises from light-induced oxygen vacancies. The dominant mechanism driving vacancy formation is identified, allowing unprecedented control over the 2DEG carrier density.
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211, Geneva, Switzerland.
authors.forename: Siobhan McKeown
authors.initials: SM
authors.lastname: Walker
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211, Geneva, Switzerland.
authors.forename: Flavio Yair
authors.initials: FY
authors.lastname: Bruno
authors.affiliation: Swiss Light Source, Paul Scherrer Institute, 5232, Villigen, Switzerland.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211, Geneva, Switzerland.
authors.forename: Alberto
authors.initials: A
authors.lastname: de la Torre
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211, Geneva, Switzerland.
authors.forename: Sara
authors.initials: S
authors.lastname: Riccó
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211, Geneva, Switzerland.
authors.forename: Anna
authors.initials: A
authors.lastname: Tamai
authors.affiliation: Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, UK.
authors.forename: Timur K
authors.initials: TK
authors.lastname: Kim
authors.affiliation: Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, UK.
authors.forename: Moritz
authors.initials: M
authors.lastname: Hoesch
authors.affiliation: Swiss Light Source, Paul Scherrer Institute, 5232, Villigen, Switzerland.
authors.forename: Ming
authors.initials: M
authors.lastname: Shi
authors.affiliation: Quantum-Phase Electronics Center, Department of Applied Physics, University of Tokyo, 113-8656, Tokyo, Japan.|RIKEN Center for Emergent Matter Science, 351-0198, Wako, Japan.
authors.forename: Mohammad Saeed
authors.initials: MS
authors.lastname: Bahramy
authors.affiliation: SUPA School of Physics and Astronomy, University of St Andrews, KY16 9SS, St Andrews, UK.
authors.forename: Phil D C
authors.initials: PD
authors.lastname: King
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211, Geneva, Switzerland.|Swiss Light Source, Paul Scherrer Institute, 5232, Villigen, Switzerland.|SUPA School of Physics and Astronomy, University of St Andrews, KY16 9SS, St Andrews, UK.
authors.forename: Felix
authors.initials: F
authors.lastname: Baumberger
keywords: 2D electron gas; angle-resolved photoemission spectroscopy; oxygen vacancies; strontium titanate