PT  - JOURNAL ARTICLE
AU  - Schröter, Niels B. M.
AU  - Robredo, Iñigo
AU  - Klemenz, Sebastian
AU  - Kirby, Robert J.
AU  - Krieger, Jonas A.
AU  - Pei, Ding
AU  - Yu, Tianlun
AU  - Stolz, Samuel
AU  - Schmitt, Thorsten
AU  - Dudin, Pavel
AU  - Kim, Timur K.
AU  - Cacho, Cephise
AU  - Schnyder, Andreas
AU  - Bergara, Aitor
AU  - Strocov, Vladimir N.
AU  - de Juan, Fernando
AU  - Vergniory, Maia G.
AU  - Schoop, Leslie M.
TI  - Weyl fermions, Fermi arcs, and minority-spin carriers in ferromagnetic CoS<sub>2</sub>
AID  - 10.1126/sciadv.abd5000
DP  - 2020 Dec 01
TA  - Science Advances
PG  - eabd5000
VI  - 6
IP  - 51
4099  - http://advances.sciencemag.org/content/6/51/eabd5000.short
4100  - http://advances.sciencemag.org/content/6/51/eabd5000.full
SO  - Sci Adv2020 Dec 01; 6
AB  - Magnetic Weyl semimetals are a newly discovered class of topological materials that may serve as a platform for exotic phenomena, such as axion insulators or the quantum anomalous Hall effect. Here, we use angle-resolved photoelectron spectroscopy and ab initio calculations to discover Weyl cones in CoS2, a ferromagnet with pyrite structure that has been long studied as a candidate for half-metallicity, which makes it an attractive material for spintronic devices. We directly observe the topological Fermi arc surface states that link the Weyl nodes, which will influence the performance of CoS2 as a spin injector by modifying its spin polarization at interfaces. In addition, we directly observe a minority-spin bulk electron pocket in the corner of the Brillouin zone, which proves that CoS2 cannot be a true half-metal.