Borisenko, SergeyEvtushinsky, DaniilGibson, QuinnYaresko, AlexanderKoepernik, KlausKirnp, TimurAli, Mazharvan den Brink, JeroenHoesch, MoritzFedorov, AlexanderHaubold, ErikKushnirenkoHD, YevhenSoldatov, IvanSchaefer, RudolfCava, Robert J.2019-08-132019-08-132019-08-132019-07-3110.1038/s41467-019-11393-5https://infoscience.epfl.ch/handle/20.500.14299/159737WOS:000477952600009Spectroscopic detection of Dirac and Weyl fermions in real materials is vital for both, promising applications and fundamental bridge between high-energy and condensed-matter physics. While the presence of Dirac and noncentrosymmetric Weyl fermions is well established in many materials, the magnetic Weyl semimetals still escape direct experimental detection. In order to find a time-reversal symmetry breaking Weyl state we design two materials and present here experimental and theoretical evidence of realization of such a state in one of them, YbMnBi2. We model the time-reversal symmetry breaking observed by magnetization and magneto-optical microscopy measurements by canted antiferromagnetism and find a number of Weyl points. Using angle-resolved photoemission, we directly observe two pairs of Weyl points connected by the Fermi arcs. Our results not only provide a fundamental link between the two areas of physics, but also demonstrate the practical way to design novel materials with exotic properties.Multidisciplinary SciencesScience & Technology - Other Topicsdiscoveryfermionssemimetalelectrongastext::journal::journal article::research article