2019/03/01 by Noam Morali, Rajib Batabyal, Pranab Kumar Nag +7 · 2 citations
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.other
paper · pdf · doi:10.1126/science.aav2334
arxiv created 2019/03/01 · arxiv updated 2019/09/23
Bulk-surface correspondence in Weyl semimetals assures the formation of topological "Fermi-arc" surface bands whose existence is guaranteed by bulk Weyl nodes. By investigating three distinct surface terminations of the ferromagnetic semimetal Co3Sn2S2 we verify spectroscopically its classification as a time reversal symmetry broken Weyl semimetal. We show that the distinct surface potentials imposed by three different terminations modify the Fermi-arc contour and Weyl node connectivity. On the Sn surface we identify intra-Brillouin zone Weyl node connectivity of Fermi-arcs, while on Co termination the connectivity is across adjacent Brillouin zones. On the S surface Fermi-arcs overlap with non-topological bulk and surface states that ambiguate their connectivity and obscure their exact identification. By these we resolve the topologically protected electronic properties of a Weyl semimetal and its unprotected ones that can be manipulated and engineered.