Bound States in the Continuum in All‐Dielectric Metasurface: Separation of Sub‐10 nm Enantiomers

• DOI: 10.1002/adpr.202100280
• Publication Date: 2021-12-22T18:43:36Z
• Authors: Libang Mao; Kuan Liu; Meng Lian; Jingyuan Jia; Ying Su; Haonan Ren; Lei-Ming Zhou; Tun Cao
• Keywords: Chirality; Plasmonic Nanoparticles

Enantioseparation is crucial in pharmaceutics and agrochemicals. Compared to the current chemical technique, optical enantioseparation more effective means yet hampered by weak chiral force. Recently, plasmonic nanostructures have been theoretically demonstrated excite superchiral fields that can enhance enantioselective forces. Yet, quality ( Q ) factors of resonances are limited ohmic losses intrinsically existing metals, thus hindering their applications for sorting a few nanometer size molecules (i.e., proteins DNA). Herein, dielectric metasurface consisting an array silicon (Si) rings with broken symmetry proposed. This sharp high‐ magnetic dipolar (MD) resonance caused distortion symmetry‐protected bound states continuum (BICs), so called quasi‐BIC. It shown this quasi‐BIC MD pronouncedly improve lateral force on paired enantiomers under linearly polarized illumination, offering sub‐10 nm nanoparticles chirality parameters ±0.2 1 ms. The work provides new approach enantiopurification enantioseparation, taking novel perspective discriminate separate pharmaceutical industries.