A team of researchers has made significant strides in the field of spintronics, achieving a breakthrough in detecting and controlling the motion of spins within antiferromagnets. Inspired by Mott insulators, this state-of-the-art employs 2D antiferromagnetic materials in combination with tunnel junctions, which could lead to their incorporation into next-generation electronics. This fundamental study shows the promise of antiferromagnetic materials. The group, led by a researcher from the California Institute of Technology, published their results July 10, 2025 in the journal Science.
The physics research team includes some of the world’s most prominent physicists, such as Thow Min Jerald Cham. He was the lead author of this study and is currently a postdoctoral scholar at the California Institute of Technology. Others include Xiaoxi Huang, Daniel G. Chica, Xavier Roy, Kenji Watanabe, and Takashi Taniguchi. Dan Ralph, the F.R. Newman Professor of Physics at Cornell University and a member of the Cornell Kavli Institute, produced crucial insights for the study. Kelly Luo, an assistant professor at the University of Southern California and co-corresponding author, was instrumental.
Advancements in Spintronics
The researchers’ innovative approach combines two cutting-edge fields: 2D materials and spintronics. They utilized 2D antiferromagnetic materials complemented with spin-filter tunneling detection approaches. Consequently, they were able to efficiently observe antiferromagnetic resonance with electrically-tunable damping. This approach marks a departure from previous detection approaches. Those relied on significantly larger samples, rendering them not feasible for real-world device deployments.
In their further investigation, the researchers specifically concentrated on the control of spins in the 2D antiferromagnet via spin-orbit torque. This powerful mechanism provides for highly-optimized, layer-dependent control of spin dynamics, offering dark and bright contrast to distinguish layers in a 2D crystal.
“We were mainly searching for a way to manipulate the spins so that we could detect the 2D layers separately, and we couldn’t really distinguish which layer was doing what. Then we came up with this idea, where we could break the symmetry by twisting the layers,” – Thow Min Jerald Cham
The research shows that the applied currents can produce factored forces on each defined spin layer. Predictably, these forces have no effect on those other layers whatsoever. This new approach constitutes a major breakthrough in controlling the evolution of spin dynamics and may pave the way to practical application for next-generation electronic devices.
The Role of Tunneling
Tunneling — a quantum mechanical phenomenon — is key to the researchers’ techniques. This produces quantum tunneling, where electrons can pass through barriers that would be insurmountable to classical particles. By taking advantage of this behavior, the team was then able to measure and control oscillations in spin dynamics at unprecedentedly high frequencies.
Kelly Luo emphasized the significance of this tunneling behavior in their research:
“This is one of our breakthroughs: that we’re using this tunneling behavior, which is this quantum mechanical electron behavior, to really read out these extremely fast oscillations.”
The researchers’ skill at harnessing tunneling now lays new roads toward appreciating and regulating spin motion inside these materials. This combined capability not only expands fundamental scientific understanding, but fuels the prospect of further applications in next-generation electronic systems.
Implications for Future Technology
Scientists are still just beginning to understand what these antiferromagnetic materials can do. They are deeply aware of the work left to do. Dan Ralph acknowledged that earlier attempts to detect spin dynamics were limited by sample size constraints:
“It’s not something that really scales down to any kind of useful device scale.”
As a practical achievement, they find a new approach through which twisted layers can be used efficiently to break symmetry. Finally, they’re hopeful that they can just surmount these limitations. In showing the power of antiferromagnetic materials to serve practical applications in electronics, the team’s work represents an important first step toward realizing real-world applications.
This study underscores the significant role of 2D materials in contemporary physics. It further uplifts them as models for future technological innovation.