What’s new

For the first time, scientists have discovered an entirely new form of magnetism called altermagnetism.

The researchers used state-of-the-art X-ray techniques to visualize and fine-tune this new magnetic material, which is very different from the kind of magnets we know in everyday life.

Their findings, published in Naturedemonstrate that altermagnetic materials can be precisely controlled in microscopic devices, marking a major step forward in magnetics and materials science.

Why it matters

Magnetic materials are an integral part of modern technologies, especially in data storage and microelectronics, but they come with problems, including energy and memory inefficiencies.

Altermagnetic materials offer a more ecological alternative and at the same time combine the best properties of existing magnetic classes – ferromagnetism and antiferromagnetism.

These new materials could dramatically increase device performance, potentially increasing the speed of microelectronic and digital memories by up to a thousand times. They also have the potential to advance areas such as quantum computing, which are trying to break free from highly specific applications in the laboratory.

In addition, this innovation could reduce dependence on toxic elements and significantly reduce the carbon footprint of the electronics industry by increasing the energy efficiency of electronic devices.

What to know

Ferromagnets, like the magnets commonly found on refrigerator doors, have all their magnetic moments aligned in the same direction, creating a strong external magnetic field.

In contrast, antiferromagnets feature alternating magnetic moments that cancel each other out on a macroscopic level, resulting in no external magnetic field, making materials of this kind ineffective for holding your grocery list on the fridge.

People have known about ferromagnets for millennia, but antiferromagnetism remained undiscovered until about a century ago.

But now there’s a new kid on the block: altermagnets.

Like antiferromagnets, altermagnets have antiparallel magnetic moments, meaning they have no macroscopic magnetic field. Yet they also exhibit a feature of ferromagnetism called time-reversal symmetry breaking.

According to Amin, this combination allows altermagnets to unite the best properties of both magnetic classes, opening up the potential for innovative applications in advanced electronic devices.

In this new study, researchers show that manganese telluride (MnTe) is a ferromagnet, as predicted and imaged at the nanoscale.

“This is the first time we have used these properties to image the altermagnetic structure in great detail,” Wadley said. “So this is the first time it kind of makes it real. Seeing is believing, and we can see that the altermagnetic order actually is as the theory predicts.”

But he didn’t stop there.

“To advance this research, we have shown that MnTe hosts interesting magnetic textures, and by creating devices of certain shapes, we can choose exactly what textures are formed,” Amin said. “This is a crucial step before making functional devices.”

This is all very new to science—only earlier this year did scientists report experimental evidence of altermagnets—and now this latest study has taken a critical step forward, providing a blueprint for how these materials can be manipulated that others can work from.

From increasing the performance of SSDs to enabling more efficient quantum computing, altermagnets could revolutionize the way we store and process data.

The findings also highlight the potential for reducing material waste and energy consumption in electronics, making altermagnetic materials a promising avenue for sustainable technological progress.

What will happen next?

Next up, Amin said, is the ability to use electrical currents to control the magnetic state of these materials: “That would be another huge achievement because it really leads to a proper functional device.”

“As seen over the past year, interest in altermagnetism is growing at an incredible rate,” he added. “With such an intense level of research in this area, I predict that altermagnets will have a commercial impact within 5-10 years.”

In the long term, Wadley believes altermagnets could replace the hard disk storage used in data centers around the world. In the short term, he said he will be watching for further developments in this area in 2025.

He added: “I think there’s a lot to come in the next few years. It’s probably the most vibrant area I’ve seen in the 20 years I’ve been doing research. I think there’s a lot more to come.”

Link

Amin, OJ, Dal Din, A., Golias, E., Niu, Y., Zakharov, A., Fromage, SC, Fields, CJB, Heywood, SL, Cousins, RB, Maccherozzi, F., Krempasky, J. , Dil, JH, Kriegner, D., Kiraly, B., Campion, RP, Rushforth, AW, Edmonds, KW, Dhesi, SS, Shmejkal, L., … Wadley, P. (2024). Nanoscale imaging and control of altermagnetism in MnTe. Nature, 636(8042), 348–353. https://doi.org/10.1038/s41586-024-08234-x