Stable plasmonic nano-trapping using a hybrid gold-graphene V-trench with an extremely deep potential well

Abstract

We theoretically investigated the stable plasmonic trapping of sub-50nm targets using integrated gold-graphene V-trench with extremely deep trapping potential well. A hybrid plasmonic trapping model is self-consistently built, which considers the surface plasmons excitation for supporting the scattering and gradient optical forces on the diffraction-limit broken nano-scale. It is demonstrated that trapping of 40 nm gold nano-sphere within the designed hybrid nano-V-trench is achieved via optimal laser intensity in visible spectra. More interestingly, it is observed that the hybrid nano-V-trench forms a vertical potential well having an extremely deep potential well of 85 KBT on the trapped 40 nm gold particle. Formation of an extremely high potential well can be explained by the perspective of localized electric field enhancement inside the nano-V-trench, which was reinforced by the involvement of graphene plasmons in the hybrid plasmonic system. This work can be helpful for well understanding of nanoparticles trapping with high stability, which is useful for the nano-manipulations in the applications of quantum dots lighting, SERS nano-sensor and nano sphere plasmonic lithography.