摘要
The enantiospecific detection of the chirality of substances at the nanoscale has attracted significant attention due to its importance in materials science,chemistry,and biology.This study presents,to our knowledge,a novel method for chirality detection based on transverse optical torque(OT),which leverages the transverse rotation of achiral particles induced by the transfer of chirality from the chiral particle within interference fields formed by the incident light without spin angular momentum(SAM).We demonstrate,both numerically and analytically,that by modulating the chirality of the chiral particle within a dimer system,it is possible to achieve the transfer of local SAM to the gold particle,thereby generating a transverse OT perpendicular to the light propagation direction.Furthermore,by adjusting the orientation of linear polarization in the excitation field,the respective contributions of electric and magnetic responses to the chirality-transfer-induced transverse OT can be exclusively observed separately,providing deeper insights into the underlying physical mechanisms.More importantly,the transverse OT exhibits an approximately linear dependence on the chirality parameter of the chiral particle,enabling enantiospecific detection of nanosamples.By replacing gold nanoparticles with suitable highrefractive-index dielectric materials such as germanium,the induced transverse magnetic dipolar OT can be further enhanced by more than two orders of magnitude,significantly improving the sensitivity of chirality detection and making it possible to detect weak chiral signals with exceptional precision.This work broadens the application scope of OTs in chirality detection and highlights the potential of chirality transfer mechanisms for advanced optical manipulation and the identification and analysis of chiral substances.
基金
National Natural Science Foundation of China(12274074,12134013,12174076)
Natural Science Foundation of Jiangsu Province(BK20242024)
Natural Science Foundation of Guangxi(2023GXNSFFA026002)
Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX24_0381)。
