Graphene surface modes enabling terahertz pulling force

FERRARI, HERNÁN; HERRERO, VICTOR; ZAPATA-RODRÍGUEZ, CARLOS J.; CUEVAS, MAURO

Applied Optics

OSA

Año: 2023 vol. 62

1559-128X

Plasmonic substrates are widely reported for its use in the manipulation of subwavelength particles. Here we analyze the optical force in the THz spectrum acting on a dielectric nano-particle when located close to a graphene monolayer. When lying on a dielectric planar substrate, the graphene sheet enables the nano-sized scatterer to excite a surface plasmon (SP) well confined on the dielectric surface. Under quite general conditions, large pulling forces can be exerted on the particle as a consequence of conservation of linear momentum and a self-action effect. Our results shown that the pulling force intensity criticaly depends on the particle shape and orientation. The low heat dissipation of graphene SPs pave the way for developing of novel plasmonic tweezer for applications involving biospecimens manipulation in the THz region.