At a Glance
- Scientists have found a way to harness antiferromagnetic materials, which promise ultra-fast information transfer, for a new generation of high-frequency electronics that could revolutionize modern technologies.
- Researchers successfully detected antiferromagnetic dynamics in micrometer-scale devices, a scale nearly 1,000 times smaller than previous experiments, using a technique called spin-filter tunneling through a 2D material.
- A quantum effect known as tunneling enables electrons to pass through the antiferromagnetic barrier, where changes in the material’s spin direction alter its electrical resistance, allowing for high-speed electrical detection.
- The team achieved precise control over the material’s spins by applying a spin-orbit torque, which uses an electric current to exert a targeted force on specific atomic layers.
- This breakthrough in detecting and controlling antiferromagnetic resonance demonstrates the materials’ great potential for realizing nano-oscillators for high-frequency applications, significantly advancing the field of spintronics.
Scientists have taken a significant step toward a new generation of ultra-fast electronics by discovering a method to read and control a special class of materials known as antiferromagnets. In a study published in the journal Science, researchers detailed a method to detect the behavior of these materials at a scale nearly 1,000 times smaller than previously possible, opening the door for their use in future technologies like high-frequency communications and advanced computer memory. While common ferromagnets, such as those found on a refrigerator, have atoms with magnetic orientations, or “spins,” that all point in the same direction, the spins in an antiferromagnet alternate, canceling each other out. This lack of an external magnetic field makes them challenging to study, but also promises devices that are faster and more robust.
The breakthrough relies on a device called a spin-filter tunnel junction, which is built on a scale of micrometers, or millionths of a meter. The researchers created a microscopic sandwich using layers of different materials, with a 2D antiferromagnet, chromium sulfur bromide (CrSBr), acting as a thin barrier in the middle. Using a quantum mechanical effect called tunneling, where electrons can pass through a barrier they would typically be unable to, the team was able to detect the rapid oscillations of the spins inside the antiferromagnet. When the spins move, they change the device’s electrical resistance, creating a clear signal that can be measured at extremely high frequencies.
“What we’ve done is make micrometer-scale devices where we can see strong signals, using tunnel junctions to be able to detect the spin motions electrically,” said co-corresponding author Dan Ralph, a professor of physics at Cornell University, in a press release.
Beyond simply observing these spin dynamics, the team also demonstrated precise control over them using a mechanism known as spin-orbit torque. By passing an electrical current through an adjacent layer of platinum ditelluride (PtTe2), they generated a spin flow that exerted a force on the antiferromagnet, pushing its spins into motion. The researchers cleverly engineered the device by slightly twisting the two layers of the CrSBr, which allowed them to apply this force to one atomic layer more than the other. This technique provides an unprecedented level of control, a crucial first step for programming information into future antiferromagnetic devices.
This work successfully merges the fields of 2D materials and spintronics, which is the study of using an electron’s spin to carry information. The ability to electrically detect and manipulate antiferromagnetic resonance on such a small scale shows that these materials have significant potential for creating new technologies. The researchers stated that this discovery could lead to the development of nano-oscillators that operate at frequencies far beyond those of today’s electronics, bringing the “holy grail” of antiferromagnetic technology closer to reality.
References
- Cham, T. M. J., Chica, D. G., Huang, X., Watanabe, K., Taniguchi, T., Roy, X., Luo, Y. K., & Ralph, D. C. (2025). Spin-filter tunneling detection of antiferromagnetic resonance with electrically tunable damping. Science, eadq8590. https://doi.org/10.1126/science.adq8590
- Glaser, L. B. & Cornell University. (2025, July 10). Physicists take step toward a holy grail for electron spins. Phys.Org; Cornell University. https://phys.org/news/2025-07-physicists-holy-grail-electron.html
