Physics First Ever

Scientists finally caught visual proof of 'altermagnetism'—it's a whole new third category of magnetism.

March 24, 2026

Original Paper

Visualizing spin-polarization of an altermagnet KV$_2$Se$_2$O via spin-selective tunneling

Guofei Yang, Chuang Li, Chengwei Wang, Xudong Zhao, Yifan Wan, Hengrui Gui, Guoqing Zeng, Saizheng Cao, Chuqiao Hu, Dong Chen, Yu Liu, Yu Song, Fei Liu, Lun-Hui Hu, Lin Jiao, Huiqiu Yuan

arXiv · 2603.21969

The Takeaway

For centuries, we only knew of two types of magnets: ferromagnets (like fridge magnets) and antiferromagnets. This paper visualizes a third type that has no external magnetic pull but possesses a 'split' internal structure that could allow for computers that run significantly faster and cooler than today's technology.

From the abstract

Altermagnetism, a recently identified magnetic phase that combines vanishing net magnetization with momentum-dependent spin splitting, challenges the conventional dichotomy between ferromagnets and antiferromagnets. While several candidate materials have been proposed, direct experimental evidence linking crystal symmetry, electronic structure and d-wave spin polarization remains scarce. Here we report the visualization of a metallic d-wave altermagnet in KV2Se2O. Through spin-selective scanning