Visualizing half-metallic bulk band structure with multiple Weyl cones of the Heusler ferromagnet

Abstract

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.

arXiv comment6 pages, 4 figures; Supplementary Information: 5 pages, 3 figures

References in corpus (13)

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Cited by in corpus (5)

• Half-metallic Ferromagnets, Spin Gapless Semiconductors, and Topological Semimetals Based on Heusler Alloys
• Unusual kinetic properties of usual Heusler alloys
• Topological phase transitions in strongly correlated systems: application to Co${}_3$Sn${}_2$S${}_2$
• The electronic structure of intertwined kagome, honeycomb, and triangular sublattices of the intermetallics MCo${}_2$Al${}_9$
• Nodal lines and boundary modes in topological Dirac semimetals with magnetism