发表机构
University of Guilan; International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences（吉兰大学; 波兰科学院物理研究所马格托国际研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出利用有限光子动量实现高阶波交替磁性的秩选择光学层析成像，通过理论计算验证了MnTe中相关谐波的高占比，且所需动量窗口可通过结构化近场达成。
AI 中文摘要
利用光学方法确定高阶波交替磁性序的空间秩具有挑战性，因为局域电偶极响应无法唯一分辨不同的连续谐波。本文表明，有限光子动量可将单光子自旋分辨吸收转化为秩选择层析成像。对于偶宇称ℓ波分量的平面|m|=ℓ扇区，偏振和动量角的联合傅里叶投影可分离出𝒯_ℓ∝η_ℓ q^(ℓ-2)，得到d:q⁰、g:q²、i:q⁴的层级；相位变化追踪所选磁谐波的旋转。沃德一致的有限q微观计算可重现这些幂次，无需强制设定。尽管离散晶体对称性可产生低阶局域伪影，但它们与所选动量谐波正交，在q^(ℓ-2)以下无法污染该谐波。在MnTe中，其非相对论母体序为三维g波，而自旋-轨道耦合降低了精确的相对论自旋-动量锁定对称性，第一性原理计算表明，奈尔投影A区自旋-能量对比度的傅里叶功率中超过99.9%保留在母体g波衍生的m=3谐波中。结构化近场将所需动量窗口置于实验可及范围内。
英文摘要
Identifying the spatial rank of higher-wave altermagnetic order optically is challenging because local electric-dipole response does not uniquely resolve distinct continuum harmonics. We show that finite photon momentum turns one-photon spin-resolved absorption into a rank-selective tomography. For the planar $|m|=\ell$ sector of an even-parity $\ell$-wave component, a joint Fourier projection in polarization and momentum angle isolates $\mathcal T_\ell\proptoη_\ell q^{\ell-2}$, yielding the hierarchy $d:q^0$, $g:q^2$, and $i:q^4$; phase changes track rotations of the selected magnetic harmonic. A Ward-consistent finite-$q$ microscopic calculation reproduces these powers without imposing them. Although discrete crystal symmetry can generate lower-order local aliases, they are orthogonal to the selected momentum harmonic and cannot contaminate it below $q^{\ell-2}$. In MnTe, whose nonrelativistic parent order is three-dimensional $g$ wave while spin--orbit coupling lowers the exact relativistic spin-momentum-locking symmetry, first-principles calculations show that more than $99.9\%$ of the Fourier power of the Néel-projected $A$-region spin-energy contrast remains in the parent $g$-wave-derived $m=3$ harmonic. Structured near fields place the required momentum window within experimental reach.
Comments6 pages, 3 figures
