Extended Data Fig. 3: Analysis of the helicoid arc van Hove singularity in RhSi.
From: Tunable topologically driven Fermi arc van Hove singularities
a, ARPES measured constant energy contours of 9% Ni-doped RhSi using linear vertical s-polarized synchrotron radiation at energies E = (0, − 60, − 130, − 200) meV. Guides for the eye track the surface helicoid arcs at different energies. The helicoid arc van Hove singularity in Ni0.09Rh0.91Si is located at E − EF = − 60 meV. b, Energy-momentum cut along the \(\bar{{{{\rm{M}}}}}-\bar{{{{\rm{Y}}}}}\) direction shows a hole-like dispersion. c, Energy-momentum cut along \(\bar{{{\Gamma }}}-\bar{{{{\rm{Y}}}}}\) shows an electron-like dispersion. d, Momentum distribution curve at the Fermi energy along \(\bar{{{\Gamma }}}-\bar{{{{\rm{Y}}}}}\), shows both branches of the saddle-shape dispersion with separation 0.249 Å−1. e, Raw ARPES data for Fig. 2e with energy-momentum cuts parallel to the ka-direction at kb = ( − 0.82, − 0.74, − 0.62, − 0.50, − 0.42) Å−1.
