Capacitive Enhancements of the Chiroptical Response in Plasmonic Helicoids

Abstract

Chiral plasmonics has been actively pursued since pushing its light‐matter interaction to an unnaturally extreme regime. Recently, chirality‐encoded metal–insulator–metal (MIM) motifs have promised compelling advantages in advancing chiroptic responses, as they enable a capacitive coupling and its resultant strong electric and magnetic resonances. However, the deterministic control over chiral MIM working at the visible regime is out of reach. Here, large‐area MIM resonators are demonstrated using non‐lithographically assembled chiral gold nanoparticles (helicoids) and subsequent gold layer deposition, and their boosted chiroptical responses at the visible regime are proven. The thickness of the topcoat Au and the dielectric gap can precisely tune the strength of capacitive coupling. The numerical analyses support that the optimally tuned capacitive coupling in the chiral MIM structure not only strengthens both electric and magnetic dipolar resonances but also makes their spectral positions closer to each other.

Multicomponent chiral plasmonic hybrid nanomaterials: recent advances in synthesis and applications

“… 76 Moreover, Nam and co-workers also achieved capacitively coupled strong electric and magnetic resonances by growing SiO 2 to construct chiral metal-insulator-metal (MIM) resonators. 97 Interestingly, Ouyang and co-workers performed semiconductor modifications on chiral Au NPs. They initially grew Ag on chiral Au NPs and subsequently converted them to Au@Ag 2 S and Au@CdS core–shell NPs through multiple-step transformations.…”

Novel nonlinear chiroptical scattering effects

“…[10,11,12] They tend to be quite intricate, and they can engage both electric and magnetic resonances in materials, which leads to further enhancing light-matter interactions. [13,14] quantum dots, [22] plasmonic nano-rotamers, [23] rare-earth complexes, [24,25] gold nanoplates, [26] plasmonic helicoids, [27] chiral alloyed nanorods, [28] chiral gold nanorods, [29] coated chiral nanorods, [30] aromatic oligoamide foldamers, [31] chiral crystals, [32] as well as variety of shadow grown nanostructures, [33,34] etc. Applications of such scattering effects include displays, [35] and nanorobotics, [36] among others.…”