TbPt₆Al₃: The first rare-earth-based altermagnet

Abstract

A research group led by Dr. Ryohei Oishi, Assistant Professor, Research Institute for Electronic Science, Hokkaido University (Former position was a JSPS Postdoctral Fellow at Hiroshima University), Prof. Emer. Toshiro Takabatake and Prof. Takahiro Onimaru from Hiroshima University has discovered, for the first time in the world, a rare-earth-based altermagnet. The interest in altermagnet has escalated in a wide field of magnetism due to the potential for antiferromagnetic spintronics devices.

In this study, we have grown the single-crystalline sample of TbPt₆Al₃, in which the Tb magnetic atoms decorate the honeycomb lattice. The neutron powder scattering experiments were carried out at HERMES JRR3, Japan and at MARI, RAL, UK, which determine the magnetic structure of TbPt₆Al₃. Comparison of the magnetic point group with the nontrivial spin Laue group revealed that TbPt₆Al₃ is the first rare-earth-based altermagnet classified into bulk g-wave type symmetry. Our work would contribute to understanding of the fundamental physics of altermagnetism and advancement of magnetic memory devices.

This research was published as Regular article of Physical Review B on September 10, 2025.