Correlation between unconventional spin Hall effect and crystal structure in the noncollinear antiferromagnet
Phys. Rev. B 112, 104412 – Published 8 September, 2025
DOI: https://doi.org/10.1103/9ndy-z3nt
Abstract
Noncollinear antiferromagnets have emerged as promising platforms for next-generation spintronic devices due to their unique spin textures and unconventional spin-polarized currents. However, the limited understanding of factors governing the out-of-plane spin polarization efficiency () in materials such as hinders their practical application. Here, we demonstrate a strain-engineering strategy to significantly enhance by tailoring the lattice constant of thin films. Through controlled annealing processes, we induce tunable crystalline strain in and systematically investigate its impact on spin-to-charge conversion via angle-resolved spin-torque ferromagnetic resonance measurements. Remarkably, the unconventional dampinglike torque efficiency increases by over an order of magnitude when the lattice constant approaches its equilibrium value, attributed to strain-modulated chiral spin configurations. First-principles calculations corroborate the critical role of lattice strain in amplifying anisotropic spin textures and spin-orbit coupling. This work not only elucidates the structural origin of spin polarization anisotropy in noncollinear antiferromagnets but also establishes a scalable route for designing high-efficiency spin sources compatible with semiconductor integration. The findings advance the development of low-power, all-electric spintronic devices based on strain-engineered antiferromagnetic heterostructures.