Repulsion of polarized particles from two-dimensional materials

Abstract

Repulsion of nanoparticles, molecules, and atoms from surfaces can have important applications in nanomechanical devices, microfluidics, optical manipulation, and atom optics. Here, through the solution of a classical scattering problem, we show that a dipole source oscillating at a frequency $\ensuremath{\omega}$ can experience a robust and strong repulsive force when its near-field interacts with a two-dimensional material. As an example, the case of graphene is considered, showing that a broad bandwidth of repulsion can be obtained at frequencies for which propagation of plasmon modes is allowed $0<\ensuremath{\hbar}\ensuremath{\omega}<(5/3){\ensuremath{\mu}}_{c}$, where ${\ensuremath{\mu}}_{c}$ is the chemical potential tunable electrically or by chemical doping.