  We consider the Higgs mode at nonzero momentum in superconductors and
demonstrate that in the presence of Rashba spin-orbit coupling, it couples
linearly with an external exchange field. The Higgs-spin coupling dramatically
modifies the spin susceptibility near the superconducting critical temperature
and consequently enhances the spin pumping effect in a ferromagnetic
insulator/superconductor bilayer system. We show that this effect can be
detected by measuring the magnon-induced voltage generated by the inverse spin
Hall effect.
