Scientists from the RIKEN Center for Emergent Matter Science and
collaborators have shown that they can manipulate single skyrmions—tiny
magnetic vortices that could be used as computing bits in future ultra-dense
information storage devices—using pulses of electric current, at room
temperature.
Skyrmions—tiny particles that can be moved under small electric currents
several orders lower than those used for driving magnetic domain walls—are
being studied in the hope of developing promising applications in data
storage devices with low energy consumption. The key to creating spintronics
devices is the ability to effectively manipulate, and measure, a single tiny
vortex.
Most research to date has focused on the dynamics for skyrmions a micrometer
or more in size or skyrmion clusters stabilized below room temperature. For
the current research, published in Nature Communications, the researchers
used a thin magnetic plate made up of a compound of cobalt, zinc, and
manganese, Co9Zn9Mn2, which is known as a chiral-lattice magnet. They
directly observed the dynamics of a single skyrmion, with a size of 100
nanometers, at room temperature using Lorentz transmission electron
microscopy. They were able to track the motions of the skyrmion and control
its Hall motion directions by flipping the magnetic field, when they
subjected it to ultrafast pulses of electric current—on the scale of
nanoseconds.
The group found that the skyrmion’s motion demonstrated a dynamic transition
from a pinned static state to a flow motion by way of creep motion under the
stimulus of electric current, and quantified the relatively fast velocity of
the skyrmion, over 3 meters per second.
According to first author Licong Peng, a special postdoctoral researcher at
RIKEN CEMS, “This is very exciting, because for the first time, we have been
able to use electrical currents to manipulate single skyrmions at room
temperature in chiral-lattice magnets.”
According to Xiuzhen Yu, the leader of the research group, “This research
will lead to further studies of dynamics of various topological spin
textures, leading to the development of skyrmion-based devices.”
Reference:
Dynamic transition of current-driven single-skyrmion motion in a
room-temperature chiral-lattice magnet 24 November 2021, Nature
Communications. DOI: 10.1038/s41467-021-27073-2
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