2016/11/30 by C. Y. Guo, C. Cao, M. Smidman +5 · 2 citations
Physics and Astronomy · #cond-mat.str-el #cond-mat.mtrl-sci
paper · pdf · doi:10.1038/s41535-017-0038-3
published as npj Quantum Materials 2, 39 (2017) · 18 pages, 4 figures, Supplementary Information available from journal link (open access)
arxiv created 2017/07/26 · arxiv updated 2017/07/27
Materials where the electronic bands have unusual topologies allow for the realization of novel physics and have a wide range of potential applications. When two electronic bands with linear dispersions intersect at a point, the excitations could be described as Weyl fermions which are massless particles with a particular chirality. Here we report evidence for the presence of Weyl fermions in the ferromagnetic state of the low-carrier density, strongly correlated Kondo lattice system CeSb, from electronic structure calculations and angle-dependent magnetoresistance measurements. When the applied magnetic field is parallel to the electric current, a pronounced negative magnetoresistance is observed within the ferromagnetic state, which is destroyed upon slightly rotating the field away. These results give evidence for CeSb belonging to a new class of Kondo lattice materials with Weyl fermions in the ferromagnetic state.