For nearly nine decades, the foundational rules of physics have neatly divided magnetic materials into two opposing camps: ferromagnets and antiferromagnets. This binary framework has governed our understanding of the universe, shaping everything from simple household refrigerator magnets to complex data storage systems. Now, an international team of scientists has shattered this long-standing dichotomy, confirming the existence of a third, previously unrecognized form of magnetic behavior known as altermagnetism. This landmark discovery reveals a hidden state of matter that bridges the gap between the two traditional classes and promises to spark major technological leaps in computing, electronics, and quantum systems.
The breakthrough is the result of rigorous experimental work led by a research team at the U.S. Department of Energy’s SLAC National Accelerator Laboratory. In a study published in the journal Science, the researchers presented compelling, robust evidence for altermagnetism, marking a monumental shift in fundamental physics.
"In the past few years, scientists have observed phenomena that don’t fit neatly into the ferromagnetism-antiferromagnetism dichotomy," explained lead author Daniel Jost, an associate scientist at SLAC and the Stanford Institute for Materials and Energy Sciences. "Researchers have been compiling evidence of a third type of magnetism that bridges the qualities of these two classes. We believe our results provide robust experimental confirmation that this third phase—altermagnetism—is real."
The research team concentrated their efforts on manganese telluride (MnTe), a crystalline compound that had historically been categorized as a conventional antiferromagnet. By building upon earlier theoretical and experimental research, the scientists successfully identified direct evidence of chirality—a distinct, intrinsic asymmetry within the material’s magnetic and atomic structure. This property shares conceptual similarities with the way a spiral staircase or a mechanical screw twists in a specific spatial direction, serving as an unmistakable signature of altermagnetism.
Beyond its profound implications for fundamental physics, the finding opens practical pathways for engineers and materials scientists. It could soon enable the development of advanced magnetic materials tailored specifically for future technologies, including ultra-fast memory systems, cutting-edge quantum devices, and significantly more energy-efficient data centers capable of handling the world’s exploding digital infrastructure.
Understanding the Two Traditional Types of Magnetism
Magnetism is a phenomenon familiar from everyday human experience. People encounter it constantly, whether it is a decorative refrigerator magnet holding up a photograph or a sensitive compass needle aligning precisely with the Earth’s invisible magnetic field. Yet, beneath these common interactions lies a deeply complex layer of quantum mechanics.
At the atomic level, magnetism is intimately connected to a fundamental quantum property of electrons known as spin. Although electron spin is a quantum mechanical phenomenon and does not literally mean an electron is physically spinning like a tiny ball, the particle behaves in certain respects as though it possesses its own intrinsic angular momentum. Physicists commonly describe the two possible quantum orientations of this spin simply as "up" and "down."
When these microscopic spins become organized into specific, collective patterns across a material, the substance can exhibit macroscopic magnetic properties. However, possessing magnetic order at the atomic scale does not necessarily mean a material will produce an externally detectable magnetic field that can pick up paperclips or influence a compass.
In ferromagnetic materials, electron spins align uniformly in the same direction, creating an ordered state of up-up-up or down-down-down. Their combined microscopic effects reinforce one another, producing the strong, familiar magnetic field associated with ordinary permanent magnets. Humanity has utilized materials with this ferromagnetic behavior for thousands of years, tracing back to ancient navigation tools like lodestones.
A second category of magnetism, formally identified in 1933, operates under an entirely different geometric principle. In antiferromagnets, neighboring electron spins point in strictly opposite directions, establishing an alternating up-down-up-down pattern. Because the magnetic contributions of these opposing spins directly oppose and counteract one another, they completely cancel each other out on a macroscopic scale, leaving the material with zero overall magnetization and no external magnetic field.
A Third Type of Magnetism Challenges the Old Rules
For almost ninety years, these two distinct categories provided the fundamental framework for how physicists understood magnetic order in solid materials. However, a series of puzzling experimental observations in recent years began revealing unusual behaviors that neither traditional category could fully explain.
Certain materials displayed alternating electron spins and no overall macroscopic magnetization, behaving outwardly just like conventional antiferromagnets. Yet, remarkably, these same materials could also support useful spin currents—a powerful property traditionally associated exclusively with ferromagnetic behavior. Spin currents allow information to be transmitted and processed through the localized spin properties of electrons rather than relying entirely on the traditional movement of electrical charge.
This unusual combination of traits strongly suggested to researchers that they were observing a fundamentally different class of physical phenomena. Recognizing this paradigm shift, scientists introduced the term "altermagnets" in 2022 to describe materials belonging to this proposed third magnetic classification.
The critical difference lies in the microscopic arrangement of atoms within the material’s crystal lattice. Altermagnets feature alternating spin orientations in an up-down-up-down configuration, but the underlying crystal structures surrounding the oppositely aligned spins are physically rotated relative to one another.
This subtle geometric rotation breaks a specific type of symmetry that normally exists in conventional antiferromagnets. Although the physical distinction appears minor at first glance, it dramatically alters how electrons behave within the material, allowing altermagnets to merge properties that were once considered mutually exclusive.
Scientists Find the Missing Evidence for Altermagnetism
Even as indirect experimental support for altermagnetism accumulated across the scientific community throughout the early 2020s, researchers still lacked a decisive, definitive way to prove that the phenomenon represented a genuinely distinct magnetic phase rather than an anomaly of known states.
"By 2024, there were some factors that spoke strongly in favorable terms of altermagnetism being real," Jost noted, "but there was still a missing piece to the puzzle."
That elusive missing evidence involved chirality, a fundamental property often described simply as "handedness." An object is defined as chiral when its mirror image cannot be perfectly rotated and aligned to match the original object. Human hands provide the most intuitive everyday example: a left hand and a right hand are exact mirror images of one another, but a left hand cannot fit properly or comfortably into a right-handed glove.
Inside an altermagnet, the unique geometric arrangement of atoms and electron spins creates this exact kind of handedness within the material’s electronic and magnetic architecture. Traditional antiferromagnets do not possess this characteristic chiral signature. Consequently, detecting this specific structural difference would provide a foolproof way to distinguish a true altermagnet from any material that merely shared superficial resemblances.
To test this hypothesis, the research team selected manganese telluride as their primary testing ground. For decades, the broader scientific community had classified the compound as an ordinary antiferromagnet, but recent theoretical models suggested it might actually belong to the newly proposed altermagnetic category.
Powerful X-Rays Reveal a Hidden Magnetic Signature
To investigate the intricate properties of manganese telluride, the team traveled to the European Synchrotron Radiation Facility (ESRF) in France. The facility’s advanced ID32 beamline is engineered to produce precisely controlled, highly polarized X-rays, allowing scientists to probe subtle magnetic structures that remain completely invisible to standard laboratory instruments.
The researchers utilized circularly polarized X-rays, which possess electric fields that rotate dynamically in either a left-handed or right-handed direction as the beam of light travels through space. By measuring the precise ways in which the manganese telluride crystals scattered these two distinct forms of polarized light, the team could search for definitive evidence of chirality.
"Chiral materials scatter left-handed polarized X-ray beams differently than they do right-handed beams," explained Jost. "Non-chiral materials would scatter each beam of light the same way."
The sophisticated experiment revealed a clear, unmistakable difference in the way the manganese telluride sample interacted with the two different X-ray polarizations. This distinctive chiral response matched precisely what theoretical models predicted for altermagnetism, a signal that would be entirely absent in a conventional antiferromagnet.
"This chiral signature gave us the solid experimental ground to say altermagnetism stands in a class of its own," Jost stated.
The researchers initially performed the delicate experiment in 2024. Demonstrating rigorous scientific verification, they returned to the facility in early 2025 to repeat the measurements entirely, successfully reproducing their original results and substantially strengthening the empirical foundation for the new magnetic phase.
"This technique helped us confirm that manganese telluride was really exhibiting altermagnetic properties," said Rachel Nickel, a postdoctoral scientist with the ESRF and a co-author who helped design and conduct the experiment on the ID32 beamline. "Altermagnetism was only proposed a few years ago, and the rapid progress in confirming these models is incredible."
Why Altermagnetism Could Transform Future Computers
The definitive confirmation of altermagnetism carries profound implications for spintronics, an rapidly expanding field of physics and engineering that seeks to harness electron spin alongside electrical charge to build vastly more capable electronic devices.
Conventional electronics store, transmit, and process information primarily by controlling the electrical charge of electrons moving through circuits. Spintronics introduces an additional paradigm by taking advantage of electron spin, opening up new horizons for data manipulation.
This extra functional capability could enable electronic devices that operate significantly faster, withstand external environmental interference more effectively, and consume substantially less electrical power than today’s silicon-based hardware. Such performance improvements would be especially transformative for high-density computer memory, massive enterprise data centers, and other data-intensive technologies that demand immense computational power while battling severe energy constraints.
However, the two traditional types of magnetism present distinct physical obstacles that have historically limited the widespread development of practical spintronic systems.
"Ferromagnets are too easily influenced by magnetic fields," Jost explained. "If you have a permanent magnet in your pocket and walk by a spintronic device built with ferromagnets, you could start flipping the bits, scrambling the information stored there. Antiferromagnets fix that problem, but they are practically invisible—so you can’t easily read the data stored in them or use them to drive efficient spin currents."
Altermagnets offer a uniquely valuable middle ground that bypasses both limitations. Much like antiferromagnets, their opposing microscopic spins produce zero net magnetization, helping to protect stored data against unwanted external magnetic interference and stray fields. Simultaneously, their unusual and asymmetric electronic structure allows them to generate robust, spin-polarized currents that can be easily detected and utilized to retrieve stored information.
"Altermagnets combine the best of both," Jost said. "They have zero net magnetization, so they’re stable, but they still have the capability to generate spin-polarized currents needed to easily extract information. That gives you an additional degree of freedom to work with."
A New Frontier for Quantum Technology and Electronics
The experimental confirmation of altermagnetism equips the global scientific community with an entirely new class of materials to investigate, synthesize, and engineer for advanced technological applications. By successfully merging magnetic stability with the ability to manipulate spin-based information streams, these materials could help overcome the stubborn roadblocks that have long restricted conventional spintronic devices to laboratories.
Looking ahead, the primary objective for researchers will be learning how to precisely control altermagnetic states using external stimuli such as localized light pulses and electrical fields. Scientists hope that mastering this level of control will pave the way for designing practical, scalable devices that harness these newly unlocked magnetic properties.
Although significant engineering and developmental milestones remain before these materials can be integrated into commercial electronics, the findings establish a robust, reliable experimental foundation for future innovations across quantum computing, high-density computer memory, and energy-efficient data infrastructure.
The research received partial financial support from the U.S. Department of Energy Office of Science.
