1. Orientation-dependent electronic structure in interfacial superconductors LaAlO3/KTaO3
- Author
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Xiaoyang Chen, Tianlun Yu, Yuan Liu, Yanqiu Sun, Minyinan Lei, Nan Guo, Yu Fan, Xingtian Sun, Meng Zhang, Fatima Alarab, Vladimir N. Strocov, Yilin Wang, Tao Zhou, Xinyi Liu, Fanjin Lu, Weitao Liu, Yanwu Xie, Rui Peng, Haichao Xu, and Donglai Feng
- Subjects
Science - Abstract
Abstract Emergent superconductivity at the LaAlO3/KTaO3 interfaces exhibits a mysterious dependence on the KTaO3 crystallographic orientations. Here by soft X-ray angle-resolved photoemission spectroscopy, we directly resolve the electronic structure of the LaAlO3/KTaO3 interfacial superconductors and the non-superconducting counterpart. We find that the mobile electrons that contribute to the interfacial superconductivity show strong k ⊥ dispersion. Comparing the superconducting and non-superconducting interfaces, the quasi-three-dimensional electron gas with over 5.5 nm spatial distribution ubiquitously exists and shows similar orbital occupations. The signature of electron-phonon coupling is observed and intriguingly dependent on the interfacial orientations. Remarkably, the stronger electron-phonon coupling signature correlates with the higher superconducting transition temperature. Our observations help scrutinize the theories on the orientation-dependent superconductivity and offer a plausible and straightforward explanation. The interfacial orientation effect that can modify the electron-phonon coupling strength over several nanometers sheds light on the applications of oxide interfaces in general.
- Published
- 2024
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