The Signal
SLAC Team Finds Direct Evidence of Altermagnetism in MnTe
A SLAC-led team detected a chiral magnetic structure in manganese telluride, providing direct evidence that the material is an altermagnet. The result could inform future spintronics research, though the experiment did not demonstrate a dev
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Two experiments revealed MnTe’s handedness
Experiments in 2024 and early 2025 gave a SLAC-led team what it describes as direct evidence that manganese telluride, or MnTe, is an altermagnet. The researchers detected chirality—a handed, asymmetric structure—in the material’s magnetic order, a feature they say cannot be explained by conventional antiferromagnetism alone. Their findings appeared in Science on October 29, 2026.
The team tested MnTe at the European Synchrotron Radiation Facility in France, using its ID32 beamline to direct circularly polarized X-rays at the material. By comparing how MnTe scattered left-handed and right-handed X-rays, the researchers found a difference that indicated a chiral signal. SLAC lead author Daniel Jost described the measurement this way:
“Chiral materials scatter left-handed polarized X-ray beams differently than they do right-handed beams.”
Daniel Jost, associate scientist at SLAC and the Stanford Institute for Materials and Energy Sciences, speaking to SLAC
The team first completed the experiment in 2024, then repeated it in early 2025 and confirmed the earlier result, according to SLAC. Rachel Nickel, a postdoctoral scientist with ESRF who helped design and conduct the experiment, said the technique helped confirm that MnTe showed altermagnetic properties.
Why chirality distinguishes the magnetic phases
In a ferromagnet, electron spins align in one direction, producing a net magnetic field. In an antiferromagnet, neighboring spins alternate and cancel one another, leaving no net magnetization. MnTe had long been treated as an antiferromagnet before researchers began identifying it as a possible altermagnet.
Altermagnets also have alternating spins and zero net magnetization, but their crystal structure rotates between the environments of opposite spins. That arrangement can produce a handed magnetic and electronic structure. The X-ray test targeted that distinction: conventional antiferromagnets should not produce the chiral signal the team observed.
Researchers proposed the term “altermagnet” in 2022 for materials that pair antiferromagnet-like spin arrangements with properties associated with ferromagnets. SLAC says evidence for the class had accumulated in earlier studies, but the direct observation of chirality in a candidate material supplied a missing experimental test.
Zero net magnetization, spin-polarized currents
The reported result concerns a material’s magnetic structure, not a working memory device or a quantum processor. Its technological interest comes from the combination of properties: altermagnets can have zero net magnetization, while still producing spin-polarized currents that researchers could use to carry or read information.
That combination could matter for spintronics, which uses electron spin as well as electrical charge. Ferromagnetic components can be disturbed by nearby magnetic fields; antiferromagnets avoid that net-field sensitivity but can be difficult to read and may not readily drive efficient spin currents. Jost said altermagnets “combine the best of both”: they have zero net magnetization and can generate spin-polarized currents. The report does not demonstrate a device or quantify improvements in speed or power.
Control is the next experimental question
SLAC says future research will explore how altermagnetic states can be influenced and controlled using light and electricity. Whether those methods can switch or read the states reliably in a device remains unanswered by the reported experiment. For now, the concrete result is a repeated X-ray measurement of MnTe’s handed magnetic signature at ESRF’s ID32 beamline.