Altermagnets and magnonics have both made the headlines repeatedly last year. Miina Leiviskä, a MSCA COFUND Physics for Future fellowship postdoc at the Institute of Physics of the CAS, blends these topics that have so recently upturned the world of physics. Are they at the core of future computing, or is it not so simple?
Your current research project combines altermagnets and spintronics, respectively magnonics – all very new and exciting areas of physics. Can you tell us more?
Spintronics, which encompasses my research, is an area of study that explores using the spin of electrons instead of their charge to process, store, and transfer information. For example, in memory applications, this has the potential to be more energy-efficient and non-volatile, meaning real-time data wouldn’t be lost even if power were cut off, let’s say if you accidentally unplugged your computer or suffered a blackout.
Could this be useful in extreme environments, like space missions where computers could then be turned off in hibernation or adverse environments?
Probably yes. Another possibly useful attribute of the antiferromagnetic and altermagnetic materials that I have researched is that they have a special robustness against external magnetic field perturbations as they have no net magnetic moment. This is unlike in ferromagnetic materials, that do have a net magnetic moment, which are commonly used in spintronics applications.
Making spin currents more robust
So in your research, you aim to find more stable alternatives?
Yes. During my PhD, and continuing now, I have been working on antiferromagnetic and altermagnetic materials. In these, the spins are aligned in opposite directions, canceling out the overall magnetic moment. This makes them more stable against external magnetic field perturbations. Most recently, I have been working on altermagnets, predicted by an international team including Tomáš Jungwirth from the FZU. These materials combine some properties of ferromagnets and some of antiferromagnets, which makes them robust against magnetic fields while retaining useful functionalities that antiferromagnets don’t possess. Essentially, what I’ve been doing is trying to explore the functionalities of materials that have been theoretically predicted to be altermagnetic and find out, for instance, how can you manipulate the orientation of the spins and store information?
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Does this kind of research require highly specialized laboratory equipment?
The nanofabrication process of these materials is comparable to conventional transistor manufacturing, using standard lithography techniques. For measuring their properties, we mainly need temperature control, such as a cryostat, an external field to manipulate spin orientation, and devices to measure the electrical transport properties, such as resistivity.
Once information is stored, does it remain stable even at room temperature?
That depends on the material. Magnetic materials have a critical temperature below which their spin order is stable. For example, the material I studied during my PhD is ordered at 110 K – about –160 °C, almost as cold as you’d get for instance on Saturn’s moon Titan – and my current material orders at just 7 K. However, there are materials that order at room temperature, so practical applications are possible.
It seems to be like room-temperature quantum computing is seen as a “holy grail”. Could spintronics contribute to achieving it?
I'm not so well versed in quantum computing applications of spintronics but since quantum effects are generally easily perturbed by thermal noise, room-temperature operation seems like a challenging research direction.
The field is expanding
Your work is co-supervised by Tomáš Jungwirth, one of the key discoverers of altermagnets, and Helena Reichlová, whose research focuses among other things on utilizing waste heat from computing. Could your materials contribute to that field?
They could! In spintronics, we aim to move spins around, and one way to do that is by using temperature gradients – essentially converting waste heat into useful spin currents, akin to the more conventional approach of using an electric field to move them. This is an important aspect of my current work with insulating materials, where spin transport relies entirely on magnons, quantized spin waves, rather than the charge of electrons.
I admit it’s quite hard to wrap one’s head around – sorry, I’m a biologist! Is there a way to explain the process to a lay person?
Think of diffusion – if you heat up a certain area, particles tend to spread towards cooler areas. The same applies to electrons: when one region is heated, they diffuse, carrying their spins with them. This creates a “spin current”, meaning we can transport spin information using temperature differences instead of electrical currents.
Spintronics and magnonics are relatively new fields. How many research groups worldwide focus on these topics?
It's hard to say exactly, but the number is growing. There are now dedicated conferences and workshops for spintronics and magnonics, and roadmaps outlining key research directions are being published, which shows that the field is expanding.
What do you see as the most promising future direction for this research?
I think hybrid approaches, combining conventional technologies with spintronics or magnonics, are promising. Each method has some limitations but blending them can overcome individual shortcomings.
Hybrid solutions could be the key
So it would be difficult to rely purely on magnonics for computing?
At least for now. My work is more in fundamental research, studying material properties rather than industrial applications, but from what I’ve understood, pure magnonic computing faces physical limitations. Hybrid solutions seem more feasible in the near term.
What brought you to this area of research? What interested you most when you entered the field?
During my master's, I really enjoyed a course on magnetism. I ended up doing my thesis at the University of Groningen, where I was introduced to spintronics. I found it fascinating and decided to stay in the field for my PhD and postdoc; it helps to build on what you already know.
PHYSICS FOR FUTURE (P4F) a MSCA COFUND-supported fellowship programme with a goal of recruiting 60 postdoctoral fellows into the Institute of Physics of the Czech Academy of Sciences and ELI Beamlines, so as to pursue topics in physics relevant to society and the economy. The first call was highly successful, and the second one opens in August 2025.
What specifically brought you to Physics for Future and Prague?
Helena Reichlová, who leads the group here, collaborated with my PhD supervisor, and through that connection, I got to know her team. When I was finishing my PhD, I reached out to see if there were opportunities to work together, and she introduced me to the P4F program. The ability to create my own research program, and at the same time having a joint mentorship between theory and experiment, was a big draw for me. It’s really valuable when you have experimental results that you need help interpreting.
Do you find the fellowship useful in other ways, like soft skills training or networking?
Definitely. I like that I have the freedom to take my project in the direction I find interesting while still having supervisor support. It’s a nice step between being a PhD student and leading one’s own research group. The program also encourages outreach, which I appreciate. Otherwise, it’s easy to get caught up in experiments and not make time for things like education or science fairs.
What do you think is most important when reaching out to students?
I think it’s about showing them what’s possible. When you’re a student, you don’t always know the full range of career paths in science. Even now, I’m sometimes surprised! It’s incredible, and I think it’s important to give students concrete examples so they can see themselves in those roles. And to “expect the unexpected”!
Can you give an example of an unexpected result in your research and how you figured it out?
During my PhD, we studied a material called manganese silicide, which we thought was an antiferromagnet. But when we measured its transport properties, we saw an effect that wasn’t supposed to happen. Collaborators in theoretical physics helped us understand that the material was actually an altermagnet. It was a good example of how experiments can lead to surprising discoveries when combined with theory.
How do you find life in Prague? Do you have time for hobbies?
I really like it here! The city is big, but not overwhelming, and I love the trams. I’ve also done some pottery – I was surprised to see how ubiquitous it is here –, which is a great way to unwind. After a day of thinking, working with my hands is a nice change.
Miina Leiviskä moved from chemistry to nanoscience to magnonics, and from Finland to the Netherlands and France to most recently find a position as a Physics for Future fellow at the Institute of Physics of the CAS in Prague. Her current research focus is studying the potential of altermagnetic magnons in next-generation energy-efficient information technologies.