Nonreciprocal Transport in KTaO_{3}-Based Interface Superconductors with Parity Mixing

Spin-triplet pairing of superconductivity, drawing huge attention by enabling future technologies in quantum computing, spintronics, and other fields, can host unique transport phenomena. Here, we report gigantically enhanced nonreciprocal transport in the superconducting fluctuation regime of KTaO_{3}-based interface superconductors. Notably, the observed nonreciprocity undergoes a sign reversal compared to the normal state. Combining experimental observations with theoretical modeling, we identify its dominant mechanism as the vortex motion and parity mixing of spin-singlet and spin-triplet pairings. We also provide evidence for an attractive spin-triplet pairing interaction. Furthermore, the nonreciprocal response is highly tunable by orders of magnitude using electrostatic gating. These findings shed light on the pairing mechanisms in Rashba superconductors and offer new pathways for developing nonlinear superconducting devices.