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For the first time, researchers have observed a square grid of merons and antimerons-small magnetic vortices and antivortices that form in a thin plate of the spiral magnet Co 8 Zn 9 ] Mn 3 . By modifying a magnetic field applied perpendicular to the slab, researchers could induce a transformation between square lattices of merons antimerons and a hexagonal grid of scormations, another form of swirl that is topologically different than merons and antimerones.
The ability to manipulate nanometer scale spin textures like merons and skyrmions is a key to the development of electronic spintronics generation electronic devices that are very low in power consumption. The secret of their low energy consumption is that they use the topological spin texture ̵
1; a property that occurs when the electrons interact in a solid.
To perform the experiments published in Nature the group used was a thin magnetic sample made of an alloy of cobalt, zinc and manganese, Co. Zn 9 Mn 3 known as a chiral magnet. They used an extremely weak magnetic field to coax the small swirls formed in the thin sample and observed them with Lorentz electron microscopy.
Xiuzhen Yu from the RIKEN Center for Emergent Matter Science (CEMS), the first author of the magazine, says: “It is well known in nature that external stimuli can trigger a structural transition of crystals between tetragonal and hexagonal lattices, and it had been predicted that this should be seen in topological spin-textures as well. It was very satisfactory to show that this idea was really true when we witnessed the merons turned into shrinkage when we carefully increased the magnetic field.
However, the experiments gave the researchers some surprises. According to Yu, “We found that the shields were very robust and lasted even when we lowered the temperature of the sheet, but the merons and antimerones were much more sensitive and relaxed when the temperature dropped. . This can have consequences for manipulating these textures in future spintronic devices. In the future, we plan to do studies using not only magnetic anisotropy but also local loads to control spin-textures. “
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X. Z. Yu et al., Transformation between meron and skyrmion topological spin textures in a chiral magnet, Nature (2018). DOI: 10,1038 / s41586-018-0745-3