Perturbation of single metal nanoparticles on a single terahertz nanoresonator

Abstract

In this work, we investigate whether single metallic nanoparticles fitted into a nanoresonator with the width similar to the size of the nanoparticle can be detected using a terahertz (THz) wave with sub-millimeter wavelength. Strikingly, one or two single gold nanoparticles inside the THz resonator induce a noticeable modulation of the THz transmission through the resonator. Depending on the size and the position of the nanoparticle, the resonant THz transmission curves have been dramatically changed. This ability would pave a new way for detecting nanoparticles in infrared and THz regimes and tuning the resonant THz transmissions as the position of the nanoparticles into the THz resonator is fully controlled using an optical trapping.