Translated by Milo
22. 2. 2024
Business Newsletter #10
Good morning,
Let me start by saying that the numbers of subscribers are growing! Considering that I launched this service a month ago and the only growth channel at the moment is my website, I'll gladly call it an achievement, proving my point and deserving further development. And I reckoned such a quasi momentous event would warrant something a bit special. Which is why, as a subscriber, you're getting access to the "archive" where all past newsletters are published too. And as the numbers continue to grow, I'll keep working on more stuff (I'm already toying with several ideas that I'd like to implement soon).
Published by iRozhlas on 15 February 2024.
They don't stick to the fridge like classic magnets, but we could still use them to store data. Czech experts from the Institute of Physics of the Academy of Sciences have discovered a third group of magnetic materials. This groundbreaking discovery could significantly impact the future of electronics. They have found magnetism in materials that were previously considered unsuitable for data storage. Roughly 200 crystals have even better properties than those used today.
We know from school that what's magnetic sticks to the fridge, while non-magnetic things fall off. But now, thanks to Czech scientists, it turns out there's something in between.
"Altermagnets don't stick to the fridge, but when you pass an electric current through them, they carry magnetic information essentially the same way a ferromagnet would," specifies Tomáš Jungwirth from the Institute of Physics of the Academy of Sciences, describing the new group of materials named altermagnets by the scientists.
Electrons affect magnetism, and we can imagine them as swans. When they're all white and floating in the same direction, the substance is magnetic (ferromagnetic). If white swans alternate with black ones, they essentially cancel out and nothing happens (antiferromagnetic). However, if a white swan is perpendicular to a black one, a magnetic field is created, but only inside. That's why the material doesn't stick to the fridge. But this is precisely what gives it such a huge advantage in terms of potential use in electronics.
"It turns out that these magnets without an external magnetic field can be switched thousands of times faster, meaning that one could have memory that would be a thousand times faster than what we have in today's hard drives," explains the main author of the study, Libor Šmejkal from the Institute of Physics, who also works at the University of Mainz. The capacity for data storage could also be several times greater.
Czech scientists began studying antiferromagnets, non-magnetic materials, about ten years ago. First, they discovered that one of the materials exhibited internal magnetism, concluding that the reason was the internal symmetry of the electrons.
"We found that there is simply a clear dividing line that separates crystals that cannot exhibit this behavior from crystals that all exhibit this behavior," explains Jungwirth.
When they then compared a thousand known crystals, the result astonished them. "We have found around 200 materials that fit precisely into this third category," which is according to Libor Šmejkal essentially twice as many as purely magnetic materials.
"There's been a lot of interest in this emerging field from scientific groups all over the world, so more and more materials are being discovered. There's practically a new article on this topic every day because scientists are excited that these materials could eliminate the drawbacks of antiferromagnets and ferromagnets while bringing completely new possibilities in terms of basic research and potential applications."
Theoretical calculations have now been experimentally verified in collaboration with Swiss scientists. The current publication in the prestigious journal Nature confirmed that, in terms of magnetism, materials must be newly divided into three groups: Magnetic, non-magnetic and altermagnetic.
"And nothing else - like a fourth group - exists because we have exhausted all possibilities of symmetry that crystals in nature can have. So, it's become somewhat common now," says Jungwirth.
It's paradoxical that these are not new materials. Quite the contrary, they have been known for decades, but the scientists have found their new property because, as Tomáš Jungwirth says, they didn't look at them with the eyes of today's physicists.
"We already know more than enough about solid-state physics, and with such fine studying of the substance, we overlook some rough features in the overall picture. You need a more rudimentary tool for that. So, we went back almost a hundred years, used a 'hammer', much simpler than a fine watchmaker's tool, and it turned out that one chapter was missing there."
The Czech discovery of altermagnetic materials has stirred great interest among scientists worldwide, who are already exploring the wide possibilities of their use.