November 2025

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.

A recent study led by Dr. Amir Capua and Benjamin Assouline at the Hebrew University of Jerusalem found that the magnetic part of light plays a direct, previously overlooked role in the Faraday effect - challenging nearly 180 years of common perception in optics and magnetism.​​

The Faraday effect is a classic phenomenon where the polarization of light rotates as it passes through a material in the presence of a static magnetic field. Historically, this rotation was explained almost entirely by the electric field of light interacting with charges in the material, while the magnetic field of light was thought negligible at optical frequencies. This new research demonstrates that the oscillating magnetic field of light itself exerts a torque on atomic spins in the material and contributes meaningfully to the rotation observed.​​