Optical trapping of quantum dots in a metallic nanotrap

We present a novel optical trap structure for the confinement of a freely mobile quantum dot to a sub-diffraction-limited volume. We examine the optical forces on a single quantum dot, under excitonic resonance conditions, in the presence of resonantly enhanced electric fields in the near-field of a suitably engineered metal nanostructure. A numerical scheme to calculate the electromagnetic force on a quantum dot using an adaptive mesh refinement (AMR) FDTD code combined with microscopic material equations is employed. Numerically derived forces on a single quantum dot are presented and it is shown that the dot may be confined in the proposed structure.