Abstract
We suggest an experiment which may allow the band theory of ferromagnetism to be tested in a direct way. If a dc electric field is applied to a sample, the magnetic electrons will drift. The frequency of a spin wave of given wave vector, when viewed in the laboratory frame, will suffer a Doppler shift when compared with the case when the electric field is zero. This Doppler shift, although small, is considerably larger for the band model than the electric field dependence of the spin-wave dispersion relation for a localized spin model. We discuss the possibility of detecting the Doppler shift by measuring the phase velocity of a coupled spin-transverse-phonon wave. Similar measurements have been performed on insulators doped with paramagnetic impurities. In these measurements, high precision has been obtained by employing an interference technique which allows a null experiment to be performed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
