AI 中文总结
本研究结合多模态光学探针，分离Kitaev-Heisenberg量子磁体Na₃Co₂SbO₆孪晶的单畴磁振子响应，揭示其本征二重面内磁振子各向异性，建立通用的多畴量子磁体自旋动力学研究框架。
AI 中文摘要
具有竞争相互作用的量子磁体通常源于微观参数间的微妙平衡，因此需将本征自旋动力学与非本征无序效应区分开。本文引入多模态光学方法，结合高磁场下的磁红外光谱与畴分辨显微拉曼光谱，重构Kitaev-Heisenberg量子磁体Na₃Co₂SbO₆孪晶的本征磁激发谱。远红外光谱显示多种磁场可调的磁激发，但本征响应被孪晶畴产生的复制特征掩盖。通过关联磁红外与畴分辨拉曼光谱，分离出单畴磁振子响应，发现显著的二重面内磁振子各向异性，该各向异性远超实测面内g因子各向异性的预期值，实则由各向异性键依赖交换相互作用主导。通过整合高场、高分辨率与空间选择性光学探针，本研究建立了适用于多畴量子磁体的本征自旋动力学揭示及自旋哈密顿量约束的通用框架。
英文摘要
Quantum magnets with competing interactions often emerge from delicate balances among microscopic parameters, making it essential to disentangle intrinsic spin dynamics from extrinsic disorder effects. Here, we introduce a multimodal optical approach combining magneto-infrared spectroscopy with domain-resolved micro-Raman spectroscopy at high magnetic fields to reconstruct the intrinsic magnetic excitation spectrum of twinned crystals of the Kitaev-Heisenberg quantum magnet Na$_3$Co$_2$SbO$_6$. Far-infrared spectroscopy reveals multiple field-tunable magnetic excitations, but the intrinsic response is obscured by replica features arising from twin domains. By correlating magneto-infrared and domain-resolved Raman spectra, we isolate the single-domain magnon response and uncover a pronounced twofold in-plane magnon anisotropy. This anisotropy far exceeds that expected from the measured in-plane g-factor anisotropy and is instead dominated by anisotropic bond-dependent exchange interactions. By unifying high-field, high-resolution and spatially selective optical probes, our work establishes a broadly applicable framework for revealing intrinsic spin dynamics and constraining the spin Hamiltonian in multidomain quantum magnets.
