Spintronics is a promising approach to computer technology that utilizes the intrinsic angular momentum of electrons to process information, possibly making computers much faster and more energy-efficient. Scientists have been try out magnetic tries, or skyrmions, and just recently improved their diffusion rate by tenfold using artificial antiferromagnets, paving the method for efficient spin-based computing.
Scientists in Germany and Japan have actually been able to increase the diffusion of magnetic tries, so-called skyrmions, by an element of ten.
In todays world, our lives are inconceivable without computers. Up until now, these devices procedure information utilizing mainly electrons as charge providers, with the parts themselves warming up substantially in the procedure.
Magnetic Whirls Store and Process Information
These whirls called skyrmions emerge in magnetic metallic thin layers and can be considered as two-dimensional quasi-particles. The feasibility of developing a practical computer based on skyrmions was demonstrated by a team of scientists from Johannes Gutenberg University Mainz (JGU), led by Professor Dr. Mathias Kläui, utilizing an initial model.
2 skyrmions antiferromagnetically coupled: The spin in the center and the outdoors spins are antiparallel to each other. Credit: ill./ ©: Takaaki Dohi/ Tohoku University
Boosting Energy Efficiency
In partnership with the University of Konstanz and Tohoku University in Japan, scientists of Mainz University have actually now accomplished another action towards spin-based, unconventional computing: They were able to increase the diffusion of skyrmions by an aspect of about 10 utilizing artificial antiferromagnets, which dramatically lowers the energy consumption and increases the speed of such a prospective computer system. “The decrease of energy usage in electronic gadgets is one of the most significant difficulties in essential research study,” emphasized Professor Dr. Ulrich Nowak, who led the theoretical part of the project in Konstanz.
The Power of Antiferromagnets
What is an antiferromagnet and what is it used for? Typical ferromagnets consist of many small spins, all paired together to point in the exact same instructions, consequently producing a large magnetic moment. In antiferromagnets, the spins are lined up alternatingly antiparallel, i.e., a spin and its direct neighbors point in the opposite instructions.
In order to understand why these antiferromagnets work in this context, we require to dig a bit deeper. An extra force element develops in ferromagnetic layers perpendicular to the instructions of movement when skyrmions move very quickly. This force part pushes the skyrmions off course. Consequently, they wind up clashing with the wall, getting stuck, and blocking the path for others. At higher speeds, they can even be damaged. However, it is in theory known that this result either does not happen in antiferromagnets or it takes place to an extremely limited level.
Advancements in Synthetic Antiferromagnets
To develop such an antiferromagnet artificially, the researchers coupled two of their ferromagnetic layers in a method that the magnetization in the 2 layers is precisely aligned in opposite directions, canceling out their magnetic fields. “With this, we have actually created a synthetic antiferromagnet in which the diffusion of skyrmions is approximately ten times higher than in the individual layers,” said Klaus Raab, a physicist at JGU.
The group of researchers investigated the results of the settlement of the magnetic layers in addition to the impact of temperature and size of the skyrmions on diffusion and consequently on the movement of the skyrmions, both experimentally and through simulations. Detailed connections have actually been found: As temperature increases, the skyrmions have more energy to diffuse much faster. “The increasing diffusion seems to be attributable not only to the pure settlement of the magnetic fields but also to the involved decrease in the size of the skyrmions,” summed up Raab.
Professor Mathias Kläui, who led the study, is pleased with the productive collaboration with Tohoku University: “We have been working with this leading Japanese university for about 10 years and there are even joint research study programs. With the assistance of the German Academic Exchange Service– the DAAD– and other research study funders, over a dozen trainees from Mainz University have already taken part in exchanges with Tohoku University. I am happy that this collective effort has actually been enabled through this cooperation.”
The research results have actually been released just recently in the journal Nature Communications.
Reference: “Enhanced thermally-activated skyrmion diffusion with tunable effective gyrotropic force” by Takaaki Dohi, Markus Weißenhofer, Nico Kerber, Fabian Kammerbauer, Yuqing Ge, Klaus Raab, Jakub Zázvorka, Maria-Andromachi Syskaki, Aga Shahee, Moritz Ruhwedel, Tobias Böttcher, Philipp Pirro, Gerhard Jakob, Ulrich Nowak and Mathias Kläui, 11 September 2023, Nature Communications.DOI: 10.1038/ s41467-023-40720-0.
These whirls called skyrmions emerge in magnetic metallic thin layers and can be considered as two-dimensional quasi-particles. The expediency of producing a practical computer based on skyrmions was demonstrated by a team of researchers from Johannes Gutenberg University Mainz (JGU), led by Professor Dr. Mathias Kläui, utilizing a preliminary model. “With this, we have actually created an artificial antiferromagnet in which the diffusion of skyrmions is around ten times greater than in the specific layers,” said Klaus Raab, a physicist at JGU. The team of scientists examined the results of the settlement of the magnetic layers in addition to the impact of temperature and size of the skyrmions on diffusion and subsequently on the movement of the skyrmions, both experimentally and through simulations. “The increasing diffusion seems to be attributable not just to the pure compensation of the magnetic fields but also to the involved reduction in the size of the skyrmions,” summarized Raab.
