Chirality Transfer and Induction Across Multiscales Using Chiral Plasmonic Structures and Macroscopic Deformation

ConspectusChiral materials are anticipated to play a significant role in next-generation technologies such as displays, information storage, optical/quantum communications, and polarization imaging due to their ability to selectively absorb and emit circularly polarized light (CPL) through chirality-dependent light-matter interactions.Highly efficient conversion of the unique optical signals generated by chiroptical responses into electrical signals─and vice versa─is crucial for advanced chiroptical applications. However, molecularly chiral materials often suffer from low chiroptical activities and low-efficiency conversion. To address this limitation, researchers have been actively developing not only novel chiral molecules but also chiral plasmonic structures (CPSs) that can effectively interact with CPL. Furthermore, efforts are underway to boost chiroptical performance of hybrid systems comprising chiral molecules and CPSs by optimizing their synergistic interactions.CPSs have emerged as promising candidates for practical applications in CPL sensors, emitters, and various photonic devices due to their preferential and strong interactions with CPL. In contrast to the chiroptical responses of molecularly chiral materials, which typically exhibit weak interactions with CPL, CPSs demonstrate strong, tunable, and even reconfigurable chiroptical responses across a broad range of wavelengths (or frequencies) from the ultraviolet to the terahertz regimes originating from the coupling of chirality with plasmonic effects, enabling localized electromagnetic field enhancements.This Account focuses on the mechanisms of chirality transfer, chirality induction, and the methodological fabrication strategies of CPSs, with a specific emphasis on the role of macroscopic deformations including twisting, rotating, stretching, bending, folding, pushing, and pulling. By employing these macroscale mechanical deformations, novel CPSs with unprecedented functionality can be readily fabricated, thereby encoding macroscopic chirality onto the micro- and nanoscale. The plasmonic chirality induction can be achieved by introducing symmetry breaking into the achiral plasmonic structures, transforming them into systems that exhibit strong chiroptical responses such as circular dichroism (CD) and optical rotatory dispersion (ORD). These responses can be dynamically tuned by modulating the applied macroscopic deformations.In addition to discussing current advancements, this Account also outlines potential future research directions in this emerging field, including the exploration of hybrid methods that combine top-down and bottom-up approaches with macroscopic deformation-based techniques, as well as the investigation of other approaches for macroscopic deformation, which has not yet been used in the field of chiral plasmonics.