Arnault, E G, Al-Tawhid, A H, Salmani-Rezaie, S, Muller, D A, Kumah, D P, Bahramy, M S, Finkelstein, G & Ahadi, K 2023, ' Anisotropic superconductivity at KTaO 3 (111) interfaces ', Science Advances, vol. 9, no. 7 . https://doi.org/10.1126/sciadv.adf1414
A two-dimensional, anisotropic superconductivity was recently found at the KTaO 3 (111) interfaces. The nature of the anisotropic superconducting transition remains a subject of debate. To investigate the origins of the observed behavior, we grew epitaxial KTaO 3 (111)-based heterostructures. We show that the superconductivity is robust against the in-plane magnetic field and violates the Pauli limit. We also show that the Cooper pairs are more resilient when the bias is along [11 2 ¯ ] (I ∥ [11 2 ¯ ]) and the magnetic field is along [1 1 ¯ 0] ( B ∥ [1 1 ¯ 0]). We discuss the anisotropic nature of superconductivity in the context of electronic structure, orbital character, and spin texture at the KTaO 3 (111) interfaces. The results point to future opportunities to enhance superconducting transition temperatures and critical fields in crystalline, two-dimensional superconductors with strong spin-orbit coupling.
