The introduction of a strong Rashba spin–orbit coupling has been predicted to enhance the spin
motive force (SMF) (see Kim et al 2012 Phys. Rev. Lett. 108 217202). In this work, we predict further
enhancement of the SMF by time modulation of the Rashba coupling aR, which induces an additional
electric field Ed me z m R = ´ a˙ R e (ˆ ). When the modulation frequency is higher than the magnetization
precessing frequency, the amplitude of this field is significantly larger than previously predicted
results. Correspondingly, the spin torque on the magnetization is also effectively enhanced. We also
suggest a biasing scheme to achieve rectification of SMF, i.e., by application of a square wave voltage at
the resonant frequency. Finally, we numerically estimate the resulting spin torque field arising from a
Gaussian pulse time modulation of aR.