发表机构
Queen’s University; University of Victoria（女王大学; 维多利亚大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究证明无损耗各向同性偶极粒子无法在任何环境中获得轴向光扭矩，但形状各向异性（如手性椭球）可产生对映体差异巨大的扭矩，实现手性分离。
AI 中文摘要
我们证明，在各向同性、无损耗的偶极粒子局部嵌入均匀、无损耗的宿主介质中时，无论其自身手性如何，在任何光照条件下、任何光子环境中，该粒子都无法感受到轴向光扭矩——这一普遍恒等式将自由空间中球体的结果推广到任意手性和基底耦合环境。形状各向异性是关键的逃逸路径，由此产生的扭矩并非普遍存在：针对手性介电椭球体，封闭形式的辐射反作用修正极化率表明，其无损耗“光扳手”扭矩在对映体之间（κ → -κ）变化达一个数量级，这是任何球体都无法实现的机械响应。在如金或硅等高折射率或有损耗基底上方，驻波增强，或仅在近接触间隙处使用更大的粒子，即可使其超过光扭矩扳手阈值。
英文摘要
We show that an isotropic, lossless dipolar particle, locally embedded in a homogeneous, lossless host, cannot experience axial optical torque under any illumination, in any photonic environment, whatever its own chirality--a general identity extending the sphere-in-free-space result to arbitrary chiral and substrate-coupled environments. Shape anisotropy is the essential escape route, and the resulting torque is not generic: closed-form, radiative-reaction-dressed polarizabilities for a chiral dielectric ellipsoid show its loss-free "optical spanner" torque changing by an order of magnitude between enantiomers (κ\to -κ), a mechanical response impossible for any sphere. Above a high-index or lossy substrate like gold or silicon, standing-wave enhancement, or simply a larger particle at a near-contact gap, brings it beyond optical-torque-wrench thresholds.
Comments8 pages, 2 figures
