  Using a well-focused soft X-ray synchrotron radiation beam, angle-resolved
photoelectron spectroscopy was applied to a full-Heusler-type Co$_2$MnGe alloy
to elucidate its bulk band structure. A large parabolic band at the Brillouin
zone center and several bands that cross the Fermi level near the Brillouin
zone boundary were identified in line with the results from first-principles
calculations. These Fermi level crossings are ascribed to majority spin bands
that are responsible for electron transport with extremely high spin
polarization especially along the direction being perpendicular to the
interface of magneto-resistive devices. The spectroscopy confirms there is no
contribution of the minority spin bands to the Fermi surface, signifying
half-metallicity for the alloy. Furthermore, two topological Weyl cones with
band crossing points were identified around the $X$ point, yielding the
conclusion that Co$_2$MnGe could exhibit topologically meaningful behavior such
as large anomalous Hall and Nernst effects driven by the Berry flux in its
half-metallic band structure.
