Toward Magneto‐Plasmonic Functionality in a Self‐Assembled Device Based on Colloidal Synthesis

Abstract

The confinement of surface plasmon polaritons (SPPs) offers strong field strengths also for longitudinal field components. Phenomena like spin‐momentum locking can thus be exploited for novel functionality in nanodevices. External control of transport or directional coupling of propagating SPPs would be highly interesting for applications. Herein, the coupling of noble metal and magnetic nanoparticles to a silver nanowire acting as SPP waveguide using a hybrid self‐assembly approach is demonstrated. A designated setup is reported to isolate and investigate magnetically controlled transport in such devices. Various configurations are measured to quantify the required sensitivity for the typically tiny magnet response at moderate strengths of the magnetic field. Although magnetic control cannot be achieved, the required improvements can be estimated based on a heuristic numerical model. It is suggested using an approach to enhance magnetic response using a combination of metal and magnetic nanoparticles. Such devices can be assembled in principle with self‐assembly approach in a multistep process.