Symmetry Enhanced Unconventional Spin Current Anisotropy in a Collinear Antiferromagnet

Abstract

Spin-orbit torque (SOT) presents a promising avenue for energy-efficient spintronics devices, surpassing the limitations of spin transfer torque. While extensively studied in heavy metals, SOT in antiferromagnetic quantum materials remains largely unexplored. Here, we investigate SOT in epitaxial FeSn, a collinear antiferromagnet with a kagome lattice. FeSn exhibits intriguing topological quantum features, including two-dimensional flat bands and Dirac-like surface states, making it an ideal platform for investigating emergent SOT properties. Using spin-torque ferromagnetic resonance, we uncover a six-fold symmetric damping-like SOT in epitaxial-FeSn/Py heterostructures, reflecting the six-fold symmetry of the epitaxial [0001]-oriented FeSn films. Additionally, we observe a substantial unconventional field-like torque, originating from spin currents with out-of-plane spin polarization. This torque exhibits a unique angular dependence-a superposition of six-fold crystalline symmetry and uniaxial symmetry associated with the antiferromagnetic spin Hall effect. Notably, the unconventional field-like torque is enhanced when the RF current flows along the Neel vector in FeSn. Our findings reveal an unconventional spin current anisotropy tunable by crystalline and magnetic symmetry, offering a novel approach for controlling SOT in antiferromagnetic spintronics.

References in corpus (20)

• Control of spin-orbit torques through crystal symmetry in WTe2/ferromagnet bilayers
• Dirac fermions and flat bands in the ideal kagome metal FeSn
• Tilted spin current generated by the collinear antiferromagnet RuO2
• Strong, anisotropic anomalous Hall effect and spin Hall effect in chiral antiferromagnetic compounds Mn${}_{3}X$ ($X$ = Ge, Sn, Ga, Ir, Rh and Pt)
• Spin-polarized current in non-collinear antiferromagnets
• Controlling spin current polarization through non-collinear antiferromagnetism
• Thickness dependence of spin-orbit torques generated by WTe2
• Layer-dependent spin-orbit torques generated by the centrosymmetric transition metal dichalcogenide $\beta$-MoTe${}_2$
• Dirac Fermions in Antiferromagnetic FeSn Kagome Lattices with Combined Space Inversion and Time Reversal Symmetry
• Anisotropic spin Hall effect from first principles
• Quasi 2-D magnetism in the Kagome layer compound FeSn
• Magnetic asymmetry induced anomalous spin-orbit torque in IrMn
• Origin of the Magnetic Spin Hall Effect: Spin Current Vorticity in the Fermi Sea
• Anomalous Hall and Nernst effects in epitaxial films of topological kagome magnet Fe3Sn2
• Charge-spin current conversion in high quality epitaxial Fe/Pt systems: isotropic spin Hall angle along different in-plane crystalline directions
• Intrinsic spin Hall effect in noncubic crystals
• Spin wave-driven variable-phase mutual synchronization in spin Hall nano-oscillators
• Interfacial origin of unconventional spin-orbit torque in Py/$\gamma -$IrMn${}_3$
• Atomic Layer Epitaxy of Kagome Magnet Fe${}_3$Sn${}_2$ and Sn-modulated Heterostructures
• Magnetic Proximity induced efficient charge-to-spin conversion in large area PtSe${}_2$/Ni${}_{80}$Fe${}_{20}$ heterostructures