Superconductivity with enhanced critical field ant the interface of oxides

YRLG Workshop: Correlation and Topology in magnetic materials, July 16th - 18th 2024

Kaveh Ahadi

KTaO3 is an incipient ferroelectric and band insulator. The emergent superconductivity at the interfaces of KTaO3 strongly depends on the interfacial crystallographic orientation. The nature of superconductivity and its interplay with strong spin–orbit coupling at the KTaO3 interfaces remain a subject of debate. I will talk about our recent experiments on epitaxial growth and superconductivity of KTaO3 heterostructures. Our results show that superconductivity is robust against the in-plane magnetic field, with the critical field of superconductivity reaching ∼25 T in optimally doped heterostructures. The superconducting order parameter is highly sensitive to the carrier density and orientation of the magnetic field. The strong violation of Pauli limit for the upper critical field of the KTaO3 interfaces is due to spin–orbit coupling which motivates the formation of anomalous quasiparticles with vanishing magnetic moment. These results offer design opportunities for superconductors with extreme resilience against the applied magnetic fields.

 

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  2. H Al-Tawhid, S. J Poage, S. Salmani-Rezaie, A. Gonzalez, S. Chikara, D. A Muller, D. P Kumah, M. N Gastiasoro, J. Lorenzana, K. Ahadi, Nano Letters 23 (15), 6944-6950 (2023)
  3. T. Schwaigert, S. Salmani-Rezaie, M. R Barone, H. Paik, E. Ray, M. D Williams, D. A Muller, D. G Schlom, K. Ahadi, Journal of Vacuum Science & Technology A 41 (2) (2023)