Physics

Geology

Electron

Fermi Gamma-ray Space Telescope

Fermi surface

Weyl semimetal

Mathematics

Semimetal

Band gap

Materials science

Surface (topology)

Geometry

Condensed matter physics

Fermi level

Superconductivity

Quantum mechanics

Arc (geometry)

Science

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.

Fermi-arc diversity on surface terminations of the magnetic Weyl semimetal Co 3 Sn 2 S 2