Journal Article

FZJ-2017-01883

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Energetic, spatial, and momentum character of the electronic structure at a buried interface: The two-dimensional electron gas between two metal oxides

Nemšák, S.FZJ* ; Conti, G. ; Gray, A. X. ; Palsson, G. K. ; Conlon, C. ; Eiteneer, D. ; Keqi, A. ; Rattanachata, A. ; Saw, A. Y. ; Bostwick, A. ; Moreschini, L. ; Rotenberg, E. ; Strocov, V. N. ; Kobayashi, M. ; Schmitt, T.FZJ* ; Stolte, W. ; Ueda, S. ; Kobayashi, K. ; Gloskovskii, A. ; Drube, W. ; Jackson, C. A. ; Moetakef, P. ; Janotti, A. ; Bjaalie, L. ; Himmetoglu, B. ; Van de Walle, C. G. ; Borek, S. ; Minar, J. ; Braun, J. ; Ebert, H. ; Plucinski, L.FZJ* ; Kortright, J. B. ; Schneider, C. M.FZJ* ; Balents, L. ; de Groot, F. M. F. ; Stemmer, S. ; Fadley, C. S.

2016
Inst. Woodbury, NY

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Please use a persistent id in citations: http://hdl.handle.net/2128/13879  doi:10.1103/PhysRevB.93.245103

Abstract: The interfaces between two condensed phases often exhibit emergent physical properties that can lead to new physics and novel device applications and are the subject of intense study in many disciplines. We here apply experimental and theoretical techniques to the characterization of one such interesting interface system: the two-dimensional electron gas (2DEG) formed in multilayers consisting of SrTiO3 (STO) and GdTiO3 (GTO). This system has been the subject of multiple studies recently and shown to exhibit very high carrier charge densities and ferromagnetic effects, among other intriguing properties. We have studied a 2DEG-forming multilayer of the form [6unitcells(u.c.)STO/3u.c.ofGTO]20 using a unique array of photoemission techniques including soft and hard x-ray excitation, soft x-ray angle-resolved photoemission, core-level spectroscopy, resonant excitation, and standing-wave effects, as well as theoretical calculations of the electronic structure at several levels and of the actual photoemission process. Standing-wave measurements below and above a strong resonance have been exploited as a powerful method for studying the 2DEG depth distribution. We have thus characterized the spatial and momentum properties of this 2DEG in detail, determining via depth-distribution measurements that it is spread throughout the 6 u.c. layer of STO and measuring the momentum dispersion of its states. The experimental results are supported in several ways by theory, leading to a much more complete picture of the nature of this 2DEG and suggesting that oxygen vacancies are not the origin of it. Similar multitechnique photoemission studies of such states at buried interfaces, combined with comparable theory, will be a very fruitful future approach for exploring and modifying the fascinating world of buried-interface physics and chemistry.

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Contributing Institute(s):

1. Elektronische Eigenschaften (PGI-6)

Research Program(s):

1. 522 - Controlling Spin-Based Phenomena (POF3-522) (POF3-522)

Appears in the scientific report 2017

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Database coverage:
; ; ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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