%0 Journal Article
%A Martínez, Emanuel Alberto
%A Dai, Ji
%A Tallarida, Massimo
%A Nemes, Norbert Marcel
%A Bruno, Flavio Yair
%T Anisotropic electronic structure of the 2D electron gas at the AlO_x/KTaO_3(110) interface
%D 2023
%U https://hdl.handle.net/20.500.14352/102962
%X Oxide-based 2D electron gases (2DEGs) have generated significant interest due to their potential for discovering novel physical properties. Among these, 2DEGs formed in KTaO_3 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 KTaO_3 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.
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