Gallium chiral nanoshaping for circular polarization handling

In this work we report the local growth of ordered arrays of 3D core-shell chiral nanohelices based on plasmonic gallium metal. The structures can be engineered in a single step using focused ion beam induced deposition, where a Ga+ ion source is used to shape the metallic nanohelix core, while the dielectric precursor is dissociated to create dielectric shells. The solubility of gallium in the different investigated dielectric matrices controls the core-shell thickness ratio of the nanohelices. The chiral plasmonic behaviour of these gallium-based nanostructures is experimentally measured by circularly polarized light transmission through nanostructure arrays and compared with numerical simulations. Large chiroptical effects in the visible range are demonstrated due to the plasmonic effects arising from gallium nanoclusters in the core.

Automated summary

In this study, locally grown ordered arrays of 3D core-shell chiral nanohelices based on plasmonic gallium metal were reported. These structures were engineered using focused ion beam induced deposition, with gallium solubility in different dielectric matrices controlling the core-shell thickness ratio. Experimental measurements and numerical simulations demonstrated large chiroptical effects in the visible range due to plasmonic effects arising from gallium nanoclusters in the core.