Violation of the Pauli limit at KTaO3(110) interfaces

The superconducting order parameter at the KTaO3 interfaces and its dependence on interface orientation remains a subject of debate. The superconductivity at these interfaces exhibits strong resilience against in-plane magnetic field and violates Pauli limit. The interface orientation dependence of critical field and violation of Pauli limit, however, have not been investigated. To address this problem, we grew epitaxial LaMnO3/KTaO3 heterostructures using molecular beam epitaxy. We show that superconductivity is extremely robust against the in-plane magnetic field. The critical field to the Pauli limiting field coincides with the (111) interfaces for the same carrier density. This suggests that the orientation of the surface does not play a critical role in determining the ratio, despite the strong impact on the critical temperature. These results offer opportunities to engineer superconductors which are resilient against magnetic field.