Incommensurate Magnetism Drives Singular Angular Magnetoresistance in the Magnetic Weyl Semimetal CeAlGe
Phys. Rev. Lett. 136, 086702 – Published 24 February, 2026
DOI: https://doi.org/10.1103/fdds-f72t
Abstract
We demonstrate that a multi- incommensurate magnetic state in the Weyl semimetal CeAlGe gives rise to a singular angular magnetoresistance (SAMR), which is an electrical transport signature capable of detecting magnetic field direction with exceptional precision. In contrast, its sister compound CeAlSi is devoid of both multi- order and SAMR. We reveal that both phenomena appear upon 57% Ge substitution in and coincide with electronic structure changes that soften the single-ion in-plane anisotropy and enhance Weyl-mediated magnetic interactions. These results unveil a remarkable connection between band topology, electronic transport, and collective magnetism in Weyl semimetals.