The hot topic material of YIG strikes again in this week’s pick, but this time it’s for a rare foray into the confusing world of magnonics. “Electric-Field Coupling to Spin Waves in a Centrosymmetric Ferrite” in PRL by Zhang et al shows that spin-orbit coupling (SOC), previously thought to be very small in YIG, can make an appreciable appearance in experiment. Control of spin-waves is desirable for low energy consumption applications, and this paper demonstrates the ability to manipulate spin wave phase via the application of an electric field, largely as a result of SOC (which is enhanced in YIG if orbital hybridisation is taken into account). This manifestation of SOC in YIG, which is a centosymmetric material, appears only in the configuration that a spin wave propagating through the YIG, an electric field applied to the YIG, and the magnetization of the YIG are all perpendicular to one another, a situation realised in this paper’s experiment. The experiment confirms that the phase of a spin wave in YIG can be altered via the electric field with the effect largely attributed to SOC with a small contribution from the magnetoelectric effect as the YIG magnetization is altered by the electric field. The mechanism is confirmed as it agrees with theoretical predictions, and also disappears as the electric field is moved parallel to the magnetization.
Also an honourable mention to Kyoung-Wham Kim for the quality of his pun in the title of his recent nature news and views article “Spintronics: SHEs electric”. Unfortunately I will never be able to beat that pun, especially as it is based around a fairly low key Oasis song, so please enjoy it and give it a read.