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Updated: May 12, 2025
Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures
Published on: February 8, 2018
Orientation-dependent superconductivity and electronic structure of the rare-earth metal/KTaO3interfaces
Guowei Yang1, Weifan Zhu1, Jiawen Zhang1
1Center for Correlated Matter and School of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China.
Abstract:
The recent discovery of orientation-dependent superconductivity in KTaO3-based interfaces has attracted considerable interest, while the underlying origin remains an open question. Here we report a different approach to tune the interfacial electron gas and superconductivity by forming interfaces between rare-earth (RE) metals (RE being La, Ce, Eu) and KTaO3substrates with different orientations. We found that the interfacial superconductivity is strongest for the Eu/KTaO3interfaces, becomes weaker in La/KTaO3and is absent in Ce/KTaO3. Usingin-situphotoemission, we observed distinct valence bands associated with RE metals, as well as a pronounced orientation dependence in the interfacial electronic structure, which can be linked to the orientation-dependent superconductivity. The photoemission spectra show similar double-peak structures for the (111) and (110) oriented interfaces, with an energy separation close to the LO4 phonon of KTaO3. Detailed analyses suggest that this double-peak structure could be attributed to electron-phonon coupling, which might be relevant for the interfacial superconductivity.
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