Spin and orbital Edelstein effect in spin-orbit coupled noncentrosymmetric superconductors

Superconductors without inversion symmetry can exhibit a nonzero magnetization when a supercurrent is present, leading to nondissipative magnetoelectric effects. Here, we focus on understanding the relation between the spin and orbital properties of these effects in spin-singlet noncentrosymmetric superconductors with orbital Rashba coupling. Our findings indicate that the correlation between spin and orbital moments induced by supercurrents is generally not determined by the sign of atomic spin-orbit coupling but rather by the number of bands at the Fermi level and the orbital characteristics of those bands with respect to the mirror parity. The outcomes demonstrate that the sign change of the orbital Edelstein effect near avoiding crossing bands remains robust despite modifications to the atomic spin-orbit amplitude. Furthermore, we observe that the spin Edelstein effect is typically one order of magnitude smaller than the orbital Edelstein effect, but can be significantly enhanced in certain scenarios with increased atomic spin-orbit coupling.