Elecromagnetic generation and detection of dc/ac spin current

It is shown that in a heterostructure where screening is eliminated, the Amp\'ere-Maxwell law of electrodynamics implies that a dc or ac spinomotive force can be inudced with a time rate of change of a transverse electric field, and the magnetic analog of Amp\'ere law implies that a dc or ac spin current can generate a transverse electric field at the same frequency outside the spin-current channel. Both effects are quite weak but may be of some usefulness.