Physics Nature Is Weird

Scientists figured out how to make heat take a sharp 'sideways' turn inside a material, even without using magnets to pull it.

April 6, 2026

Original Paper

Observation of anomalous thermal Hall effect in altermagnets

Wenbo Wan, Xu Zhang, Yixuan Luo, Yanfeng Guo, Shiyan Li

arXiv · 2604.03183

The Takeaway

Usually, pushing heat to the side requires a strong magnetic field, but this new class of 'altermagnets' does it naturally. This reveals a strange new way to control how energy moves through solids without needing external magnets.

From the abstract

Altermagnets, recently proposed as a third category of collinear magnets, combine the features of zero net magnetization in antiferromagnets and the spin splitting in ferromagnets. While abundant spectroscopic evidence for altermagnetism has been reported, experimental observation of the anomalous Hall effect, a hallmark of ferromagnetism, remains scarce. Here, we present systematic measurements of the thermal Hall effect in two representative altermagnet candidates, MnTe and CrSb. In both mater