A new breakthrough in the field of future magnetic storage devices has been sounded with success in experiments by researchers from Johannes Gutenberg University Mainz (JGU) and Massachusetts Institute of Technology (MIT) in magnetic skyrmions. This builds upon the success of the international team in March.
The team achieved billion-fold reproducible motion of skyrmions on different positions and makes a critical step in pushing the application of skyrmions in complex devices.
The experiments suggested skyrmions can be ideal for futuristic spintronic applications including skyrmion racetrack memories and logic devices.
The work was published in the research journal Nature Physics.
"In highly competitive fields of research such as that on skyrmions, international cooperation with leading groups is a strategical advantage," said Professor Mathias Kläui of the JGU Institute of Physics, also the Director of MAINZ.
Film Structure Experiments
The team carried out experiments in specially designed thin film structures. The structures were similar to a hair whorl and had unique stability justifying application of skyrmions in spintronic devices.
The property of skyrmions shifting under electrical currents and moving relatively undisturbed is essential for racetrack devices, where magnetic bits shuffle in the track.
What makes them suitable is the robustness and ability to stay unaffected by defects including edge roughness.
In the experiments, Skyrmion Hall effect was in good display abetted by a non-zero topological charge with skyrmions taking transverse velocity as in charged particles.
The dynamics of skyrmions while being powered by current-induced spin-orbit was better revealed by nanoscale pump-probe imaging. It also showed, movement of skyrmions exceeding 30° angle and belying theoretical expectations in respect of the flow of current.
Advantage Skyrmions
From a commercial perspective, this holds promise as skyrmions — by virtue of being nanoscale magnetic whirlpools — are expected to create efficient ways for storing data.
As matter's new quantum mechanical state, the industry sees it as ideal in making smaller, energy efficient gadgets that emit less heat.
Research on skyrmions is proving that it can feed rising demands for processing and storing of large data by addressing the limitations of hard drive technology.
The advent of skyrmions was predicted in 1962, and they were only discovered in 2009 as tiny swirling patterns in magnetic fields quite amenable to manipulation.
The flexibility of skyrmions owes it to the internal structure where magnetic moments point in different directions. Being structured in self-organised vortex shape makes the couplings of atoms weak yet tightly packed as fields are locked by strong forces.
This makes skyrmion patterns robust in the magnetic storage of information, unlike ferromagnetic domains in gadgets like computers and smartphones. Skyrmions also score highly in respect of the less energy needed in moving them.
Meanwhile, research is progressing on new alternative storage solutions. Perovskite materials with the alterable magnetic order without disrupting the material is one solution. They are being mooted as a replacement for silicon-based systems and also as a choice for next generation of hard drives.
