Radiative Pulling Forces, Exerted by Evanescent Fields Along a Hyperbolic Metamaterial Slab

We show and investigate in detail the optical pulling forces acting on a particle in the vicinity of a waveguiding structure made of a hyperbolic metamaterial. We have shown analytically that if the waveguide dispersion is negative, the longitudinal radiative force outside of hyperbolic metamaterial is always a pulling force, that is directed toward the source of electromagnetic energy flow in contrast to the common situation when a strong propulsion force emerges near the surface of an open waveguide.