This record is currently in review state, the data hasn’t been validated yet.
Chiral magnetism, current-driven domain walls and thermal spin drag in magnetic insulators with perpendicular anisotropy
- Conference Paper
Magnetic insulators (MIs), especially iron-based garnets, possess remarkable properties such as low damping, long magnon decay lengths, and high structural quality, providing a suitable playground for spintronics research and potential applications. Recently, robust perpendicular magnetic anisotropy is obtained in ferrimagnetic thin films of thulium, europium, and terbium iron garnet (TmIG, EuIG, and TbIG) grown on Gadolinium Gallium Garnet (GGG) substrates down to a thickness of 5.1 nm with saturation magnetization close to the bulk value . By using the spin Hall effect in Pt, we have demonstrated efficient spin current injection through the TmIG/Pt interface quantified by the spin Hall magnetoresistance and harmonic Hall effect measurements. This spin current is strong enough to achieve spin-orbit torque-driven magnetization switching of TmIG(~10 nm)/Pt bilayer with efficiencies comparable to or exceeding that of, e.g., Pt/Co . We then investigated the magnetic texture and current-driven dynamics of domain walls in this system. We found that the domain walls can be efficiently moved using electrical currents in the absence of external fields, indicating the presence of Néel-type domain wall textures. Further analysis revealed that the chiral domain walls are stabilized due to the Dzyaloshinkii-Moriya interaction at the substrate GGG/TmIG interface. We found that these chiral domain walls can be propelled faster than 800 m/s per current densities as low as 1.2x1012 A/m2, one of the highest reported in any ferromagnetic system thus far . Finally, we will discuss a new thermoelectric effect that we have recently discovered, which allows electrical detection of out-of-plane magnetization component in magnetic insulators by using temperature gradients in a nonlocal device. The effect relies on efficient spin pumping and spin drag, respectively driven by out-of-plane and in-plane temperature gradients, generated by a single heater source. We measure an inverse spin Hall effect voltage in Pt, orthogonal to both the MI magnetization vector and the in-plane temperature gradient, to which we coin the name thermal spin drag voltage, highlighting its origins. Show more
External linksSearch via SFX
Organisational unit03986 - Gambardella, Pietro / Gambardella, Pietro
MoreShow all metadata