Giant spin Hall angle in the Heusler alloy Weyl ferromagnet Co${}_2$MnGa

Abstract

Weyl semimetals are playing a major role in condensed matter physics due to exotic topological properties, and their coexistence with ferromagnetism may lead to enhanced spin-related phenomena. Here, the inverse spin Hall effect (ISHE) in the ferromagnetic Weyl-semimetal Heusler alloy Co${}_2$MnGa was investigated at room temperature by means of electrical spin injection in lateral spin valve structures. Spin transport properties such as spin polarization and spin diffusion length in this material were precisely extracted in order to estimate the spin Hall angle ${\theta }_{\text{SH}}$, which was found to be $-0.19\pm 0.04$ and is among the highest reported for a ferromagnet. Although this value is on the same order of magnitude of known heavy metals, the significantly higher resistivity of Co${}_2$MnGa implies an improvement on the magnitude of detection voltages, while its ferromagnetic nature allows controlling the intensity of SHE through the magnetization direction. It was also shown that Onsager's reciprocity does not hold for this system, which is in part attributable to a different spin-dependent Hall conductivity for spin-up and spin-down carriers.

14 pages with 13 figures including supplemental materials

References in corpus (6)

• Topological Weyl semimetals in the chiral antiferromagnetic materials Mn3Ge and Mn3Sn
• Topological Hopf and chain link semimetal states and their application to Co2MnGa (Theory and Materials Prediction)
• Onsager Relations in Coupled Electric, Thermoelectric and Spin Transport: The Ten-Fold Way
• Control of spin injection by direct current in lateral spin valves
• Skew scattering in dilute ferromagnetic alloys
• Spin diffusion length of Permalloy using spin absorption in lateral spin valves

Cited by in corpus (8)

• Giant intrinsic anomalous terahertz Faraday rotation in the magnetic Weyl semimetal Co${}_2$MnGa at room temperature
• Unusual kinetic properties of usual Heusler alloys
• Spin Hall effect in a spin-1 chiral semimetal
• Spintronic THz emitters based on transition metals and semi-metals/Pt multilayers
• Gigantic Anisotropy of Self-Induced Spin-Orbit Torque in Weyl Ferromagnet Co2MnGa
• Spin Hall Conductivity and Anomalous Hall Conductivity in Full Heusler compounds
• Anomalous sign inversion of spin-orbit torque in ferromagnetic/nonmagnetic bilayer systems due to self-induced spin-orbit torque
• Deposition temperature dependence of thermo-spin and magneto-thermoelectric conversion in Co${}_2$MnGa films on Y${}_3$Fe${}_5$O${}_{12}$ and Gd${}_3$Ga${}_5$O${}_{12}$