A new kind of magnetism could unlock faster, more efficient computers

A newly identified layered altermagnet could help unlock faster, thinner, and more energy-efficient computers powered by electron spin.

The computers of the future may rely on more than the electrical charge carried by electrons. Researchers are increasingly interested in another fundamental electron property called spin, which could provide a new way to move and process information inside electronic devices.

Conventional computers use the movement of electrical charge to handle data. If scientists can reliably control electron spin as well, they may be able to develop entirely new approaches to computing that operate faster and consume less energy.

A research team led by UCF Professor of Physics Madhab Neupane has now identified a material that could help make that possible. Neupane and his collaborators found experimental evidence of altermagnetism, a recently recognized form of magnetism that combines useful features associated with two better known magnetic states: ferromagnetism and antiferromagnetism.

Ferromagnetism is the type of magnetic behavior familiar from ordinary magnets. In a ferromagnetic material, magnetic moments point in the same direction, producing an overall magnetic field.

That behavior can be valuable in electronic technologies, but it comes with a drawback. Ferromagnets can generate stray magnetic fields that interfere with surrounding components, a growing concern as electronic devices become smaller and more densely packed.

Antiferromagnets work differently. Their magnetic moments point in opposite directions, effectively canceling one another and greatly reducing stray magnetic fields. However, these materials do not possess some of the electronic characteristics that make ferromagnets attractive for technological applications.

Like antiferromagnets, they can operate without creating unwanted stray magnetic fields. At the same time, they can generate and detect spin currents, meaning the movement of electron spins through a material. Researchers are investigating whether these spin currents could eventually carry information through future electronic systems.

Neupane and his collaborators found experimental signatures of altermagnetism in Co1/4TaSe2, a layered material that contains magnetic cobalt atoms. The material could now serve as a flexible experimental platform for studying this unusual magnetic state while potentially helping advance electronic and spintronic technologies.

"These materials are distinguished from more conventional antiferromagnets by their ability to generate and detect spin currents without the negative effect of producing stray fields," Neupane says. "This new property makes them very well positioned for use in many different applications -- including spintronics, ultrafast memory devices, terahertz networks and energy-efficient electronics."

To determine whether Co1/4TaSe2 really displayed altermagnetism, the researchers examined how electrons behaved inside the material.

They used angle-resolved photoemission spectroscopy, or ARPES, a technique that allows researchers to measure the energy and motion of electrons and reconstruct a material's electronic structure.