Anisotropic Electronic Structure of the 2D Electron Gas at the AlOx/KTaO3(110) Interface
Abstract Oxide‐based 2D electron gases (2DEGs) have generated significant interest due to their potential for discovering novel physical properties. Among these, 2DEGs formed in KTaO3 stand out due to the recently discovered crystal face‐dependent superconductivity and large Rashba splitting, both o...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley-VCH
2023-10-01
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| Series: | Advanced Electronic Materials |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/aelm.202300267 |
| _version_ | 1797662958812135424 |
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| author | Emanuel A. Martínez Ji Dai Massimo Tallarida Norbert M. Nemes Flavio Y. Bruno |
| author_facet | Emanuel A. Martínez Ji Dai Massimo Tallarida Norbert M. Nemes Flavio Y. Bruno |
| author_sort | Emanuel A. Martínez |
| collection | DOAJ |
| description | Abstract Oxide‐based 2D electron gases (2DEGs) have generated significant interest due to their potential for discovering novel physical properties. Among these, 2DEGs formed in KTaO3 stand out due to the recently discovered crystal face‐dependent superconductivity and large Rashba splitting, both of which hold potential for future oxide electronics devices. In this work, angle‐resolved photoemission spectroscopy is used to study the electronic structure of the 2DEG formed at the (110) surface of KTaO3 after deposition of a thin Al layer. The experiments reveal a remarkable anisotropy in the orbital character of the electron‐like dispersive bands, which form a Fermi surface consisting of two elliptical contours with their major axes perpendicular to each other. The measured electronic structure is used to constrain the modeling parameters of self‐consistent tight‐binding slab calculations of the band structure. In these calculations, an anisotropic Rashba splitting is found with a value as large as 4 meV at the Fermi level along the [−110] crystallographic direction. This large unconventional and anisotropic Rashba splitting is rationalized based on the orbital angular momentum formulation. These findings provide insights into the interpretation of spin‐orbitronics experiments and help to constrain models for superconductivity in the KTO(110)‐2DEG system. |
| first_indexed | 2024-03-11T19:07:39Z |
| format | Article |
| id | doaj.art-d602d6792aaa47118bbfdab2371e20fe |
| institution | Directory Open Access Journal |
| issn | 2199-160X |
| language | English |
| last_indexed | 2024-03-11T19:07:39Z |
| publishDate | 2023-10-01 |
| publisher | Wiley-VCH |
| record_format | Article |
| series | Advanced Electronic Materials |
| spelling | doaj.art-d602d6792aaa47118bbfdab2371e20fe2023-10-10T05:50:40ZengWiley-VCHAdvanced Electronic Materials2199-160X2023-10-01910n/an/a10.1002/aelm.202300267Anisotropic Electronic Structure of the 2D Electron Gas at the AlOx/KTaO3(110) InterfaceEmanuel A. Martínez0Ji Dai1Massimo Tallarida2Norbert M. Nemes3Flavio Y. Bruno4GFMC Departamento de Física de Materiales Universidad Complutense de Madrid Madrid 28040 SpainALBA Synchrotron Light Source Cerdanyola del Vallès 08290 Barcelona SpainALBA Synchrotron Light Source Cerdanyola del Vallès 08290 Barcelona SpainGFMC Departamento de Física de Materiales Universidad Complutense de Madrid Madrid 28040 SpainGFMC Departamento de Física de Materiales Universidad Complutense de Madrid Madrid 28040 SpainAbstract Oxide‐based 2D electron gases (2DEGs) have generated significant interest due to their potential for discovering novel physical properties. Among these, 2DEGs formed in KTaO3 stand out due to the recently discovered crystal face‐dependent superconductivity and large Rashba splitting, both of which hold potential for future oxide electronics devices. In this work, angle‐resolved photoemission spectroscopy is used to study the electronic structure of the 2DEG formed at the (110) surface of KTaO3 after deposition of a thin Al layer. The experiments reveal a remarkable anisotropy in the orbital character of the electron‐like dispersive bands, which form a Fermi surface consisting of two elliptical contours with their major axes perpendicular to each other. The measured electronic structure is used to constrain the modeling parameters of self‐consistent tight‐binding slab calculations of the band structure. In these calculations, an anisotropic Rashba splitting is found with a value as large as 4 meV at the Fermi level along the [−110] crystallographic direction. This large unconventional and anisotropic Rashba splitting is rationalized based on the orbital angular momentum formulation. These findings provide insights into the interpretation of spin‐orbitronics experiments and help to constrain models for superconductivity in the KTO(110)‐2DEG system.https://doi.org/10.1002/aelm.2023002672DEGARPESelectronic structureKTaO3Rashba spin–orbit coupling |
| spellingShingle | Emanuel A. Martínez Ji Dai Massimo Tallarida Norbert M. Nemes Flavio Y. Bruno Anisotropic Electronic Structure of the 2D Electron Gas at the AlOx/KTaO3(110) Interface Advanced Electronic Materials 2DEG ARPES electronic structure KTaO3 Rashba spin–orbit coupling |
| title | Anisotropic Electronic Structure of the 2D Electron Gas at the AlOx/KTaO3(110) Interface |
| title_full | Anisotropic Electronic Structure of the 2D Electron Gas at the AlOx/KTaO3(110) Interface |
| title_fullStr | Anisotropic Electronic Structure of the 2D Electron Gas at the AlOx/KTaO3(110) Interface |
| title_full_unstemmed | Anisotropic Electronic Structure of the 2D Electron Gas at the AlOx/KTaO3(110) Interface |
| title_short | Anisotropic Electronic Structure of the 2D Electron Gas at the AlOx/KTaO3(110) Interface |
| title_sort | anisotropic electronic structure of the 2d electron gas at the alox ktao3 110 interface |
| topic | 2DEG ARPES electronic structure KTaO3 Rashba spin–orbit coupling |
| url | https://doi.org/10.1002/aelm.202300267 |
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