Antiferromagnetism

Researchers from The University of Tokyo, RIKEN Center for Emergent Matter Science (CEMS), Tokyo Metropolitan University, Karlsruhe Institute of Technology (KIT), Gdańsk University of Technology, High Energy Accelerator Research Organization, Japan Atomic Energy Agency, and additional institutes recently reported a metallic “twisted” antiferromagnet that realizes p‑wave magnetism and delivers a strong, easily readable spintronic signal. This material links a helical spin texture directly to charge transport, pointing toward faster, cooler, and more compact spin‑based memory and logic technologies.

In this compound, atomic magnetic moments do not all align in one direction as in a standard magnet; instead, they form a helix along a crystal axis, creating an antiferromagnetic “twisted” state with nearly zero net magnetization. This helical texture produces an odd‑parity (p‑wave) spin splitting of the conduction electrons, so electrons moving in different directions carry oppositely polarized spins without relying on strong electronic correlations.

Researchers from China's Hangzhou Dianzi University have developed an artificial intelligence-driven framework that could accelerate the discovery of antiferromagnetic materials for spintronics. Antiferromagnets (AFMs) are prized in advanced electronics because their alternating spin orientations cancel stray magnetic fields, creating fast, stable, and densely packable devices. However, their complex magnetic interactions and vast chemical possibilities have made systematic design extremely challenging.

The team’s approach combines a crystal diffusion variational autoencoder with data augmentation (CDVAE-DA), crystal graph convolutional neural networks (CGCNNs), a genetic algorithm (GA), and density functional theory (DFT) validation into a single, integrated pipeline. CDVAE-DA learns from tens of thousands of known crystal structures and then fine tunes its predictions on an AFM-specific dataset, producing novel, chemically valid candidates with over 90% composition accuracy. These structures are rapidly screened by CGCNN models, which assess three key properties: formation energy, total magnetic moment, and electronic band gap. Candidates meeting AFM-friendly criteria—stable energy, low net magnetization, and a targeted band gap range—are passed to the optimization stage.

A rare spin effect once thought confined to bulk crystals is now confirmed in ultrathin magnetic films. This effect, known as altermagnetism, arises in a special class of antiferromagnets where electronic bands split depending on electron momentum, despite the absence of net magnetization. Unlike ferromagnets, which produce disruptive stray fields, or conventional antiferromagnets, which often conceal useful spin properties, altermagnets combine stability with robust spin-split band structures - making them attractive for spin-based devices.

A recent study by scientists from Pennsylvania State University, University of California (Santa Barbara), University of Minnesota, National Institute of Standards and Technology, Lawrence Berkeley National Laboratory, SLAC National Accelerator Laboratory, Oakridge National Laboratory and Israel's Weizmann Institute of Science demonstrated this behavior in chromium antimonide (CrSb) thin films. 

Antiferromagnets are attracting growing attention as promising complements to conventional ferromagnets. While their properties have been extensively studied, clear demonstrations of their technological advantages have remained elusive. Now, researchers from Tohoku University, the National Institute for Materials Science (NIMS), and the Japan Atomic Energy Agency (JAEA) managed to provide compelling evidence of the unique benefits of antiferromagnets. Their recent study shows that antiferromagnets enable high-speed, high-efficiency memory operations in the gigahertz range, outperforming their ferromagnetic counterparts.

The team used the chiral antiferromagnet Mn₃Sn, whose spins form a non-collinear arrangement, as the medium for writing digital information. They fabricated a nanoscale Mn₃Sn dot device and successfully induced coherent rotation of its antiferromagnetic texture using electric currents. This enabled fast, high-fidelity control of spin ordering.

Researchers from Cornell University, Columbia University and Japan's National Institute for Materials Science have demonstrated direct electrical detection of antiferromagnetic resonance in structures on the few-micrometer scale using spin-filter tunneling in PtTe₂/bilayer CrSBr/graphite junctions in which the tunnel barrier is the van der Waals antiferromagnet CrSBr. 

Ferromagnetic materials have been in use in technologies like magnetic hard drives, magnetic random access memories and oscillators for many years. But antiferromagnetic materials, if only they could be harnessed, hold even greater potential: ultra-fast information transfer and communications at much higher frequencies. Now, the researchers' recent work is a step in that direction. Their work could be beneficial for both detecting and controlling the motion of spins within antiferromagnets using 2D antiferromagnetic materials and tunnel junctions.

Researchers at MIT, Università degli Studi "Gabriele d'Annunzio", Yale University, Drexel University, Rutgers University and University of Illinois Urbana-Champaign have demonstrated a new form of magnetism that could one day be harnessed to build faster, denser, and less power-hungry spintronic memory chips.

The new magnetic state is a hybrid of two main forms of magnetism: the ferromagnetism and antiferromagnetism. Now, the MIT team has demonstrated a new form of magnetism, termed “p-wave magnetism.”

In a recent study, researchers have discovered antiferromagnetism in a real Quasicrystal (QC). The team was led by Ryuji Tamura from the Department of Materials Science and Technology at Tokyo University of Science (TUS), along with Takaki Abe, also from TUS, Taku J. Sato from Tohoku University, and Max Avdeev from the Australian Nuclear Science and Technology Organization and The University of Sydney.

Quasicrystals are solid materials that exhibit an intriguing atomic arrangement. Unlike regular crystals, in which atomic arrangements have an ordered repeating pattern, QCs display long-range atomic order that is not periodic. Due to this 'quasiperiodic' nature, QCs have unconventional symmetries that are absent in conventional crystals. Since their Nobel Prize-winning discovery, condensed matter physics researchers have dedicated immense attention toward QCs, attempting to both realize their unique quasiperiodic magnetic order and their possible applications in spintronics and magnetic refrigeration.

The University of California, Riverside, according to reports, has been awarded nearly $4 million through the UC National Laboratory Fees Research Program to lead a major research initiative in antiferromagnetic spintronics. Over the next three years, the project will explore how antiferromagnetic materials can be used to push the boundaries of modern microelectronics.

“The semiconductor microelectronics industry is looking for new materials, new phenomena, and new mechanisms to sustain technological advances,” said Jing Shi, a distinguished professor of physics and astronomy at UCR and the award’s principal investigator. “With co-principal investigators at UC San Diego, UC Davis, UCLA, and Lawrence Livermore National Laboratory, we aim to cement the University of California’s leadership in this area and obtain extramural center and group funding in the near future.”

UC Riverside has received a Collaborative Research and Training Award of nearly $4 million from the UC National Laboratory Fees Research Program to explore how antiferromagnetic spintronics can be used to advantage in advanced memory and computing. The three-year project aims to advance microelectronics using antiferromagnetic materials, an ultrafast spin-based technology.

“The semiconductor microelectronics industry is looking for new materials, new phenomena, and new mechanisms to sustain technological advances,” said Jing Shi, a distinguished professor of physics and astronomy at UCR and the award’s principal investigator. “With co-principal investigators at UC San Diego, UC Davis, UCLA, and Lawrence Livermore National Laboratory, we aim to cement the University of California’s leadership in this area and obtain extramural center and group funding in the near future.”

Researchers from Kyoto University, Chiba University, The University of Tokyo, Osaka University and Tokai University have found that the direction of spins inside a special type of magnet can be changed rapidly - flipping about every trillionth of a second - without increasing the temperature. They achieved this by applying a strong magnetic field with an oscillation frequency in the terahertz range.

The background for this work, according to the scientists, is the ever-increasing amount of information handled by computers and communication devices, that is driving development of technologies using the terahertz band - around 1012 Hz, a frequency range beyond the conventional gigahertz range of 109 Hz - considered important for the post-5G era. Additionally, memory technologies based on spintronics are expected to use less power to store more information, with antiferromagnets attracting attention because their collective spin-motion mode frequency reaches the terahertz range, making it possible to control spins using terahertz waves. However, conventional spin excitation using electric-field pulses is accompanied by heating or carrier excitation effects that subside relatively slowly, making it difficult to achieve fast spin control. The team has now demonstrated non-thermal spin switching in a canted antiferromagnet by dynamically modifying the magnetic energy landscape using a strong multicycle terahertz magnetic near-field.