Self-Trapped Nanoparticle Binding via Waveguide Mode

In this paper, we study a stable optomechanical system based on a nanoparticle chain coupled to a waveguide mode. Under the plane wave excitation, the nanoparticles form a stable self-organized periodic array along the waveguide axis through the transverse binding effect. We show that, owing to the long-range interaction between the nanoparticles, the trapping potential for each nanoparticle in the chain increases linearly with the system size, making the formation of long chains more favorable. We show that, for an optical nanofiber platform, the binding energy for two nanoparticles is in the range of 9-13 kT, reaching the value of 110 kT when the chain size is increased to 20 nanoparticles. We also suggest the geometry of the two counter-propagating plane waves excitation, which will allow trapping the nanoparticles close to the optical nanofiber, providing efficient interaction between the nanoparticles and the nanofiber.