Topography of Fermi arcs in t − PtBi 2 using high-resolution angle-resolved photoemission spectroscopy

Topological semimetals are considered important for future developments of ultralow-power fast electronics that utilize spin rather than charge for storing and processing information. Weyl semimetals are important member of this family, as they host Fermi arcs, along which the spin of electrons is locked to their momenta. In most previously studied materials, the Fermi arcs are in very close proximity to other features of the band structure (e.g., NbAs), which makes it difficult to study these objects. Here, the authors find that in $t$-PtBi${}₂$, the arcs are well separated from other features, which allows a conclusive demonstration that they are indeed disconnected contours in the momentum space, spanning two Weyl points of opposing polarity. Since the Fermi arcs in PtBi${}₂$ are the main feature in the Fermi surface, it is likely that it would be easier to harness their unusual spin properties.