发表机构
Centro Federal de Educação Tecnológica; International Iberian Nanotechnology Laboratory; Universidade do Minho（巴西联邦技术教育中心; 伊比利亚纳米技术国际实验室; 米尼奥大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究金属非磁体 KV₂Se₂O 的磁振子，揭示非磁体对称性、自旋轨道耦合对磁振子色散、各向异性衰减及能隙的调控，表明其为定向磁振子传输的有前景平台。
AI 中文摘要
我们研究非磁体氧硒钒化物中的自旋激发，重点关注金属型准二维化合物 KV₂Se₂O。采用从头计算得到的费米子哈密顿量，我们在随机相位近似框架下计算了横向自旋磁化率，并提取出磁振子色散关系。研究表明，非磁体对称性在布里渊区高对称路径的电子能带和磁振子谱中均会导致特征性的简并与方向分裂。金属型 KV₂Se₂O 因与粒子-空穴连续体耦合而呈现有限的磁振子线宽。此外，通过固定波矢大小并改变其面内方向，我们发现磁振子能量和寿命存在显著的角度依赖性，且两个磁振子分支间呈现互补的阻尼行为。当计入自旋轨道耦合后，该体系表现出垂直于平面的易 c 轴各向异性，在 Γ 点打开约 6 meV 的磁振子能隙，这可能使磁有序在室温下保持稳定。我们的结果证明，非磁体不仅调控自旋激发的色散，还调控其各向异性衰减，凸显非磁体金属是定向选择性磁振子传输的有前景平台。
英文摘要
We investigate the spin excitation in altermagnetic vanadium oxyselenides, focusing on the metallic quasi-two-dimensional compound $\text{KV}_2\text{Se}_2\text{O}$. Using a fermionic Hamiltonian derived from ab initio calculations, we compute the transverse spin susceptibilities within the random phase approximation and extract the magnon dispersion relation. We show that the altermagnetic symmetry leads to characteristic degeneracies and directional splittings in both the electronic bands and the magnon spectra along high-symmetry paths of the Brillouin zone. The metallic $\text{KV}_2\text{Se}_2\text{O}$ exhibits finite magnon linewidths arising from the coupling to the particle-hole continuum. Furthermore, by fixing the magnitude of the wave vector and varying its in-plane direction, we uncover a pronounced angular dependence of the magnon energies and lifetimes, with complementary damping behavior between the two magnon branches. Upon including spin-orbit coupling, the system exhibits an out-of-plane easy c-axis anisotropy, which opens a magnon gap of approximately 6 meV at the $Γ$-point, possibly rendering the magnetic order stable at room temperature. Our results demonstrate that altermagnetism controls not only the dispersion but also the anisotropic decay of spin excitations, highlighting altermagnetic metals as promising platforms for directionally selective magnon transport.
Comments9 pages, 7 figures
