Science Daily  September 21, 2023
One of the hallmarks of Magnetic Weyl semimetals (mWSMs) is the emergence of large intrinsic anomalous Hall effect. On heating the mWSM above its Curie temperature, the magnetism vanishes while exchange-split Weyl point pairs collapse into doubly degenerate gapped Dirac states. Researchers in Japan found potential of these Dirac nodes in paramagnetic state for efficient spin current generation at room temperature via the spin Hall effect. They introduced Ni and In to separately substitute Co and Sn in a prototypal mWSMCo3Sn2S2 shandite film and tuned the Fermi level. Composition dependence of spin Hall conductivity for paramagnetic shandite at room temperature resembled that of anomalous Hall conductivity for ferromagnetic shandite at low temperature, exhibiting peak-like dependence centering around the Ni-substituted Co2Ni1Sn2S2 and undoped Co3Sn2S2 compositions, respectively. They observed spin Hall and anomalous Hall conductivity maxima at different compositions reflecting optimum Fermi-level positioning relative to the paramagnetic Dirac and magnetic Weyl states, which suggested the common origin and intercorrelation between the two Hall effects. According to the researchers their findings highlight a strategy for the quest of spin Hall materials, guided by the abundant experimental anomalous Hall-effect data of ferromagnets in the literature… read more. TECHNICAL ARTICLE
AÂ schematic of the stack structure and high-resolution cross sectional transmission electron microscopy image for a Tri layer with Co3Sn2S2 (CSS) … Credit: Phys. Rev. B 108, 064429, 25 August 2023Â