A magnetic field is generally expected to weaken superconductivity, yet under certain conditions the superconducting response can recover after an initial suppression as the field is increased. Such re-entrant behavior is most commonly associated with bulk materials rather than strongly confined two-dimensional systems.

Here we report a re-entrant superconducting response at the epitaxial LaTiO${}_3$​/KTaO${}_3$​ (110) interface, where superconductivity develops in a gate-tunable two-dimensional electron system with strong interfacial spin-orbit coupling [1–3]. At this interface, the effect appears under in-plane magnetic field as a pronounced non-monotonic transport response and persists over a broad range of carrier densities. The realization of re-entrant behavior in an interfacial oxide system that combines low dimensionality, strong confinement, spin-orbit coupling, and electrostatic tunability establishes LaTiO${}_3$/KTaO${}_3$​ as a promising platform for studying how magnetic field reshapes superconductivity in two dimensions. We discuss the results in the context of field-induced modifications of the electronic structure and their interplay with superconductivity in KTaO${}_3$-based heterostructures.

Reference:

[1] Superconductivity at epitaxial LaTiO₃-KTaO₃ interfaces,
D. Maryenko et al. APL Materials 11, 611102 (2023)

[2] Emerging two-dimensional conductivity at the interface between Mott and
band insulator,
I. Maznichenko et al, Phys. Rev. Lett. 132, 216201 (2024)

[3] Re-entrant superconductivity at an oxide heterointerface,
D. Maryenko et al. arXiv:2510.01682