Spintronics is a new field of scientific research aimed at developing devices that
In turn, magnetic insulators are a classmaterials widely used all over the world, mainly due to their ability to conduct electrical charges. Just as metals conduct electrical charges, magnetic insulators can conduct spins. However, since spins are rarely conserved in materials and tend to disappear at large distances, until now, using magnetic insulators to achieve long-range transport seemed to be a challenge.
Researchers have recently demonstrated the transferlong-range magnetic "hedgehogs", three-dimensional topological spin structures that are often observed in ordinary magnets. The results of the research carried out will find application in the development of devices that support the ideas of spintronics.
“Our idea is to usetopological spin textures, not the spins themselves, for the purpose of long-range transport, said Shu Zhang, one of the researchers. - Magnetic "hedgehog" - one type of topologically protected spin texture, which usually exists in three-dimensional magnets. Our work shows that the "hedgehog" current is a well-conserved quantity and can be studied to achieve long-range transport in magnetic insulators. "
Zhang and her colleagues' research is based ona theoretical postulate known as topological conservation law, which allowed researchers to use the hydrodynamics idea of topological spin textures. This idea was previously explored in a series of studies led by physicist Yaroslav Tserkovnyak.
“The main theoretical approach that weapplied in our study - this is the classical field theory, - explained Zhang. We describe the space-time distribution of spins as a continuous vector field, over which topological textures and their currents can be determined and studied. The mathematical description of "hedgehog" currents is subject to the principles of the theory of electromagnetism. "
The researchers used an experimentalan installation in which a "hedgehog" current is introduced and detected using metal contacts attached to two ends of the magnet. In this scenario, the magnet could be viewed as a conductor carrying the current of topological spin textures with finite conductivity. This concept opens up huge potential for the use of magnetic insulators for long distance transportation.