Collective excitations and divergent spin currents in noncentrosymmetric superconductors
Phys. Rev. B 113, 134523 – Published 24 April, 2026
DOI: https://doi.org/10.1103/tsk3-m7v3
Abstract
We study the collective modes in a noncentrosymmetric superconductor with Rashba spin-orbit coupling under laser irradiation. The concept of Anderson Pseudospin Resonance allows us to reveal how laser driving gives rise not only to the established resonant enhancement of third harmonic response, but also to a resonant enhancement in the second-harmonic response of the spin current. We propose a theory that explains the phenomenon without including interband transitions. The theory is corroborated by numerical simulations, which incorporate interband effects and allow us to clarify the signatures of the collective modes in the long-time dynamics of the superconductor.
