Altermagnetism – Lightsources.org

SLAC researchers find proof of altermagnetism, a new magnetic phase

2026/10/292026/11/03

The team directly observed a unique property in an altermagnetic candidate material, delivering key evidence of a new phase of magnetism first postulated in 2022.

Key takeaways:

The scientific case for a third type of magnetism – termed “altermagnetism” – has been building over recent years.
Now, a SLAC-led team has experimentally proven that a material exhibits characteristics that are theoretically impossible to explain without altermagnetism.
Altermagnetic materials could be used to design advanced electronics, with applications including quantum technologies, memory devices and data centers.

For decades, physicists recognized only two types of magnetism that occur in materials without external influence: ferromagnetism and antiferromagnetism. Today, in findings published in Science, a team led by the U.S. Department of Energy’s SLAC National Accelerator Laboratory has delivered conclusive experimental proof of a third magnetic phase called altermagnetism.

“In the past few years, scientists have observed phenomena that don’t fit neatly into the ferromagnetism-antiferromagnetism dichotomy,” explained lead author Daniel Jost, associate scientist at SLAC and 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.”

Building on previous studies, this research confirmed that manganese telluride (MnTe) is an altermagnet – a new class of magnet that exhibits properties of both ferromagnetism and antiferromagnetism. Their results showed direct experimental evidence of chirality – an asymmetric magnetic structure, akin to a spiral staircase or a screw – in the spins of an altermagnetic candidate material.

Identifying these unique materials could allow researchers to manipulate their properties in ways that make them ideal candidates for advanced electronics, with applications including quantum technologies, memory devices and data centers.

A primer on magnetism

To most of us, magnetism is a tangible force: It’s what holds a child’s artwork to a refrigerator door and points a compass needle north. But to a physicist, magnetism is more complex. It’s a quantum property of a material, and not all magnetic materials have a directly observable magnetic effect.

In physics, a material is considered magnetic if its electrons’ spins – their internal angular momentum, which can be either “up” or “down” – are polarized, or ordered in a specific pattern.

In ferromagnets, all electronic spins point the same direction (up-up-up or down-down-down), creating an observable magnetic field. Humans have known about and made use of this class of magnets since ancient times. In 1933, scientists discovered another type of material with polarized spins. Antiferromagnets have alternating electronic spins (up-down-up-down) that cancel each other out, producing no net magnetic effect.

Read more on the SLAC website

A New Magnetic State for the AI Era: Demonstrating “Alternating Magnetism” in Ruthenium Dioxide Thin Films

2025/09/242025/11/20

—Toward the Development of High-Speed, High-Density Memory for AI and Data Centers—

Background and Challenges
Ruthenium dioxide (RuO₂) has long been regarded as a promising candidate for exhibiting “altermagnetism,” the so-called third type of magnetism. Conventional ferromagnets can be easily written with external magnetic fields, but stray fields cause recording errors, posing a fundamental obstacle to high-density memory. Antiferromagnets are resistant to external disturbances such as stray fields; however, because atomic spins (N–S poles) cancel each other out, electrical readout is extremely challenging.

This created the demand for a new class of magnetic material that combines the best of both worlds—robustness against disturbances while still enabling electrical readout and, potentially, future rewriting. Yet, worldwide experimental results on RuO₂’s altermagnetism have been inconsistent, and the lack of high-quality thin films with uniform crystal orientation prevented definitive demonstration.

Key Achievements
A collaborative research team from NIMS, the University of Tokyo, Kyoto Institute of Technology, and Tohoku University succeeded in fabricating single-variant RuO₂ thin films with aligned crystal orientation on sapphire substrates. By optimizing substrate choice and growth conditions, the team clarified the mechanism that determines orientation.

Using X-ray magnetic linear dichroism (XMLD) measurements at the Photon Factory synchrotron facility of KEK, the researchers identified both the magnetic order—where total magnetization (N–S poles) cancels out—and the spin orientation. They further observed spin-split magnetoresistance, a phenomenon in which electrical resistance changes depending on spin orientation, thereby confirming electronic differences in spin states by electrical means.

Read more on the KEK website

Image: Conceptual illustration of altermagnetism in single-variant RuO₂ thin films, showing XMLD signals and spin orientations

International community gathers for Diamond’s Magnetic Materials Group User Meeting

2024/06/102024/06/11

Last week, over 100 scientists from across the international research community attended the first in a series of in person User Meetings taking place in 2024 at Diamond, the UK’s national synchrotron science facility.

The Magnetic Materials Group (MMG) User Meeting, incorporating a Theory of Soft X-ray Spectroscopy Workshop, took place from Monday 3^rd – Wednesday 5^th June. Delegates heard talks from invited speakers from across Europe who shared their latest research results in areas such as altermagnetism, spin textures, strong correlated systems and functional materials. Diamond scientists presented on the facilities of the MMG, which enable a wide range of polarised X-ray based research into novel materials and phenomena. This included a presentation on one of the Diamond-II upgrade flagship beamlines I17, which will offer Coherent Soft X-ray Imaging and Diffraction (CSXID) and is currently in design phase.

Sarnjeet Dhesi, Diamond’s Science Group Leader for the MMG, says, “It was fantastic to see our user community network and discuss new collaborations that could be enabled by upgrades to our facilities. “

Lightsources.org was one of the event sponsors, along with ELMITEC and BESTEC, and supported the MMG User Meeting by providing the poster prizes. A panel chosen by the organising committee selected the three best posters and Prof. Kevin Edmonds, a Diamond User Committee representative from University of Nottingham, and Silvana Westbury, Project Manager for Lightsources.org, presented the prizes at the end of the meeting.

Winners were:

1^st prize 🏅 went to Myron Huzan for their poster on ‘Quantifying the influence of 3d-4s mixing on linearly coordinated metal ions.’

Image: Prof. Kevin Edmonds, a Diamond User Committee representative from University of Nottingham (left), and Silvana Westbury, Project Manager for Lightsources.org (centre), presenting 1st prize to Myron Huzan (right)

Credit: Stefania Mazzorana/Diamond

2^nd prize🏅, for their poster on ‘The magnetic order and excitations in GdRu2Si2’, went to George Wood.

3^rd prize🏅, for their poster on ‘Strain modulated charge ordered transitions in a highly-correlated electron material’, went to Diego Barlettani.

Diamond’s next User Meeting, which is the Spectroscopy Group User Meeting, takes place this week (registration for this event is now closed). Future User Meetings covering Extreme Conditions as well as Imaging and Microscopy will take place later in the year. Keep an eye on the Diamond and Lightsources.org websites to find out when registration opens for these in person events.

To learn more about the Magnetic Material Group, visit the Diamond website

Altermagnetism proves its place on the magnetic family tree

2024/02/142024/02/23

There is now a new addition to the magnetic family: thanks to experiments at the Swiss Light Source SLS, researchers have proved the existence of altermagnetism. The experimental discovery of this new branch of magnetism is reported in Nature and signifies new fundamental physics, with major implications for spintronics.

Magnetism is a lot more than just things that stick to the fridge. This understanding came with the discovery of antiferromagnets nearly a century ago. Since then, the family of magnetic materials has been divided into two fundamental phases: the ferromagnetic branch known for several millennia and the antiferromagnetic branch. The experimental proof of a third branch of magnetism, termed altermagnetism, was made at the Swiss Light Source SLS, by an international collaboration led by the Czech Academy of Sciences together with Paul Scherrer Institute PSI.

The fundamental magnetic phases are defined by the specific spontaneous arrangements of magnetic moments – or electron spins – and of atoms that carry the moments in crystals. Ferromagnets are the type of magnets that stick to the fridge: here spins point in the same direction, giving macroscopic magnetism. In antiferromagnetic materials, spins point in alternating directions, with the result that the materials possess no macroscopic net magnetisation – and thus don’t stick to the fridge. Although other types of magnetism, such as diamagnetism and paramagnetism have been categorised, these describe specific responses to externally applied magnetic fields rather than spontaneous magnetic orderings in materials.

Altermagnets have a special combination of the arrangement of spins and crystal symmetries. The spins alternate, as in antiferromagnets, resulting in no net magnetisation. Yet, rather than simply cancelling out, the symmetries give an electronic band structure with strong spin polarization that flips in direction as you pass through the material’s energy bands – hence the name altermagnets. This results in highly useful properties more resemblant of ferromagnets, as well as some completely new properties.

A new and useful sibling

This third magnetic sibling offers distinct advantages for the developing field of next-generation magnetic memory technology, known as spintronics. Whereas electronics makes use only of the charge of the electrons, spintronics also exploits the spin-state of electrons to carry information.

Although spintronics has for some years promised to revolutionise IT, it’s still in its infancy. Typically, ferromagnets have been used for such devices, as they offer certain highly desirable strong spin-dependent physical phenomena. Yet the macroscopic net magnetisation that is useful in so many other applications poses practical limitations on the scalability of these devices as it causes crosstalk between bits – the information carrying elements in data storage.

More recently, antiferromagnets have been investigated for spintronics, as they benefit from having no net magnetisation and thus offer ultra-scalability and energy efficiency. However, the strong spin-dependent effects that are so useful in ferromagnets are lacking, again hindering their practical applicability.

Here enter altermagnets with the best of both: zero net magnetisation together with the coveted strong spin-dependent phenomena typically found in ferromagnets – merits that were regarded as principally incompatible.

“That’s the magic about altermagnets,” says Tomáš Jungwirth from the Institute of Physics of the Czech Academy of Sciences, principal investigator of the study. “Something that people believed was impossible until recent theoretical predictions is in fact possible.”