Altermagnetism Confirmed: Scientists Prove a Third Type of Magnetism

Scientists led by the US Department of Energy’s SLAC National Accelerator Laboratory say they have delivered conclusive experimental proof of altermagnetism, a third type of magnetism first proposed in 2022, in findings published in the journal Science. The discovery could help engineers design faster and more energy-efficient electronics, including memory devices and data-centre hardware.

The team confirmed that manganese telluride (MnTe), a material long classed as an ordinary antiferromagnet, shows a “chiral” magnetic signature that cannot be explained without altermagnetism, according to Stanford University and SLAC.

What Is Altermagnetism?

For decades, physicists recognised two main types of magnetism in materials without external influence. In ferromagnets, the kind that hold notes to a fridge, all electron spins point the same way, producing an observable magnetic field. In antiferromagnets, discovered in 1933, neighbouring spins alternate (up-down-up-down) and cancel out, so there is no net magnetic effect.

In recent years, researchers noticed materials that did not fit neatly into either category. They showed features of antiferromagnets, such as alternating spins and no net magnetisation, while also behaving like ferromagnets in their ability to carry spin-polarised currents. In 2022, researchers proposed the name “altermagnets” for this class. The theory suggests the crystal lattice around the “up” spins is rotated relative to the lattice around the “down” spins, a break in symmetry that could explain their unusual behaviour.

What Did the SLAC Team Find?

“We believe our results provide robust experimental confirmation that this third phase – altermagnetism – is real,” said lead author Daniel Jost, an associate scientist at SLAC and the Stanford Institute for Materials and Energy Sciences.

“By 2024, there were some factors that spoke strongly in favour of altermagnetism being real, but there was still a missing piece to the puzzle,” Jost said. That missing piece was evidence of chirality, or “handedness”, in a candidate material: the property that means an object cannot be superimposed on its mirror image, just as a left hand will not fit a right-handed glove.

The team took manganese telluride to the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, where a beamline known as ID32 can produce precisely controlled polarised X-rays. By comparing how the material scattered left-handed and right-handed circularly polarised X-rays, they detected a clear chiral signal that “shouldn’t exist in a conventional antiferromagnet”, Stanford reported.

“This chiral signature gave us the solid experimental ground to say altermagnetism stands in a class of its own,” Jost said. The first experiment was completed in 2024 and repeated in early 2025, confirming the earlier results. “Altermagnetism was only proposed a few years ago, and the rapid progress in confirming these models is incredible,” said co-author Rachel Nickel, a postdoctoral scientist at ESRF.

Why Does It Matter for Electronics?

The main application is spintronics, a field that uses both an electron’s charge and its spin to store and move information. Spintronic devices could be faster, more robust and use significantly less power than conventional electronics, according to SLAC.

Existing materials have drawbacks. “Ferromagnets are too easily influenced by magnetic fields,” Jost explained, meaning a stray magnet could scramble stored data. “Antiferromagnets fix that problem, but they are practically invisible – so you can’t easily read the data stored in them.” Altermagnets, he said, “combine the best of both”: they have zero net magnetisation, so they are stable, but can still generate the spin-polarised currents needed to read information.

What Happens Next?

Future research will explore how altermagnetic states can be controlled using light and electricity, a necessary step before they can be used in practical devices for quantum technologies, memory and data centres. The research announcement did not give a timeline for commercial devices.

For more on the technologies shaping computing, see our look at emerging technologies that will define the next decade, and for recent discoveries in physics and astronomy, our report on the Rubin Observatory’s newly found distant object.

Featured image: The European Synchrotron Radiation Facility (ESRF) in Grenoble, France, where the experiments were carried out, by Rama / Wikimedia Commons, CC BY-SA 2.0 FR. File photo.

Sources

• Stanford Report / SLAC National Accelerator Laboratory — Researchers find proof of a new magnetic phase (29 October 2026).