Terahertz binding of nanoparticles based on graphene surface plasmons excitations

TL;DR

This paper investigates how graphene surface plasmons influence the optical binding of dielectric nanoparticle dimers, revealing controllable, sub-wavelength equilibrium positions through electromagnetic analysis.

Contribution

It introduces analytical expressions for graphene surface plasmon contributions to optical binding and demonstrates dynamic control of nanoparticle arrangements.

Findings

Surface plasmons create multiple stable binding positions.

Equilibrium distances are significantly smaller than the wavelength.

Chemical potential tuning allows dynamic control of particle positions.

Abstract

This work studies the optical binding of a dimer composed by dielectric particles close to a graphene sheet. Using a rigorous electromagnetic method, we calculated the optical force acting on each nanoparticle. In addition, we deduced analytical expressions enabling to evaluate the contribution of graphene surface plasmons (GSPs) to optical binding. Our results show that surface plasmon on graphene excitations generate multiple equilibrium positions for which the distance between particles are tens of times smaller than the photon wavelength. Moreover, these positions can be dynamically controlled by adjusting the chemical potential on graphene. Normal and oblique incidence have been considered.