Two-dimensional electron systems in perovskite oxide heterostructures: Role of the polarity-induced substitutional defects
| Autor: | Aaron Bostwick, Cheng-Tai Kuo, Jean-Pascal Rueff, Shih-Chieh Lin, Slavomír Nemšák, Eli Rotenberg, Nicolas Gauquelin, Jaap Geessinck, Y. C. Shao, Charles S. Fadley, Yi-De Chuang, Yingying Peng, Arturas Vailionis, Mark Huijben, Eric M. Gullikson, I. L. Graff, G. Conti, Claus M. Schneider, Johan Verbeeck, Giacomo Claudio Ghiringhelli |
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| Přispěvatelé: | Inorganic Materials Science, MESA+ Institute |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Physics and Astronomy (miscellaneous) Magnetism Oxide FOS: Physical sciences 02 engineering and technology Electron Conductivity Inelastic scattering 01 natural sciences chemistry.chemical_compound 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) cond-mat.mes-hall General Materials Science 010306 general physics Perovskite (structure) Condensed Matter - Materials Science Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Physics Materials Science (cond-mat.mtrl-sci) Heterojunction 021001 nanoscience & nanotechnology cond-mat.mtrl-sci 3. Good health chemistry Excited state 0210 nano-technology |
| Zdroj: | Physical Review Materials Physical Review Materials, vol 4, iss 11 Physical Review Materials, 4(11):115002. American Physical Society Physical review materials |
| ISSN: | 2475-9953 |
| DOI: | 10.1103/physrevmaterials.4.115002 |
| Popis: | The discovery of a two-dimensional electron system (2DES) at the interfaces of perovskite oxides such as LaAlO3 and SrTiO3 has motivated enormous efforts in engineering interfacial functionalities with this type of oxide heterostructures. However, its fundamental origins are still not understood, e.g. the microscopic mechanisms of coexisting interface conductivity and magnetism. Here we report a comprehensive spectroscopic investigation of the depth profile of 2DES-relevant Ti 3d interface carriers using depth- and element-specific techniques, standing-wave excited photoemission and resonant inelastic scattering. We found that one type of Ti 3d interface carriers, which give rise to the 2DES are located within 3 unit cells from the n-type interface in the SrTiO3 layer. Unexpectedly, another type of interface carriers, which are polarity-induced Ti-on-Al antisite defects, reside in the first 3 unit cells of the opposing LaAlO3 layer (~10 {\AA}). Our findings provide a microscopic picture of how the localized and mobile Ti 3d interface carriers distribute across the interface and suggest that the 2DES and 2D magnetism at the LaAlO3/SrTiO3 interface have disparate explanations as originating from different types of interface carriers. Comment: 28 pages, 4 figures; Supplemental Materials 19 pages |
| Databáze: | OpenAIRE |
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