Signatures of enhanced spin-triplet superconductivity induced by spin-orbit coupling

Through structural inversion asymmetry in superconducting junctions, the resulting interfacial spin-orbit coupling provides a versatile platform to realize proximity-induced spin-triplet superconductivity sought in superconductor spintronics and topological quantum computing. However, the signatures of such spin-triplet conductivity and the conditions for its enhancement remain debated. By calculating superconducting correlations in ferromagnet/s-wave superconductor junctions and zero-bias conductance contributions from equal-spin Andreev reflection, we reveal how very different signatures give a consistent picture for an enhanced spin-triplet superconductivity. Unlike the common expectation that strong spin-orbit coupling promotes the spin-triplet pairing or a small interfacial barrier is necessary for robust proximity effects, we reveal a more complex picture. An enhanced spin-triplet superconductivity, realized for intermediate values of spin-orbit coupling and interfacial barrier strength, is consistent with the experimentally observed huge increase in the conductance magnetoanisotropy.