2020/10/16 by Takashi Kono, Masaaki Kakoki, Tomoki Yoshikawa +6 · 1 citation
Materials Science · Physics and Astronomy · #Brillouin zone #Condensed matter physics #Electron #Electronic band structure #Fermi Gamma-ray Space Telescope #Fermi level #Ferromagnetism #Heusler alloys: electronic and magnetic properties #Magnetic field #Magnetic properties of thin films #Magnetoresistance #Materials science #Nuclear magnetic resonance #Photoemission spectroscopy #Physics #Quantum mechanics #Spin polarization #Topological Materials and Phenomena #X-ray photoelectron spectroscopy #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevlett.125.216403
published as Phys. Rev. Lett. 125, 216403 (2020) · 6 pages, 4 figures; Supplementary Information: 5 pages, 3 figures
arxiv created 2020/10/16 · openalex publication_date 2020/11/19 · arxiv updated 2020/11/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Using a well-focused soft x-ray synchrotron radiation beam, angle-resolved photoelectron spectroscopy was applied to a full-Heusler-type Co2MnGe 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 perpendicular to the interface of magnetoresistive 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 Co2MnGe could exhibit topologically meaningful behavior such as large anomalous Hall and Nernst effects driven by the Berry flux in its half-metallic band structure.