Directional surface plasmon polariton scattering using single magnetic nanoparticles.

Area of Science:

• * Plasmonics and Nanophotonics
• * Metamaterials and Nanoparticle Optics

Background:

• * Directional surface plasmon polaritons (SPPs) are crucial for energy-efficient plasmonic devices.
• * Dielectric nanoparticles offer directional scattering via coupled electric and magnetic responses.
• * Directional SPPs from magnetic nanoparticles remain underexplored.

Purpose of the Study:

• * To demonstrate and investigate directional scattered SPPs using single magnetic nanoparticles.
• * To explore the influence of magnetic properties and particle size on SPP directionality.
• * To assess the potential for enhancing plasmonic device performance.

Main Methods:

• * Utilized computational simulations to model SPP scattering from magnetic nanoparticles.
• * Conducted experimental investigations using single Fe3O4 magnetic nanoparticles.
• * Analyzed the excitation of high-order transverse electromagnetic (TEM) modes within the nanoparticles.

Main Results:

• * Achieved highly directional forward-scattered SPPs from single magnetic nanoparticles.
• * Observed enhanced forward directionality with increased particle size and permeability.
• * Experimentally recorded a maximum forward-to-backward SPP scattering ratio of 118.52:1 using a 1 μm Fe3O4 nanoparticle.

Conclusions:

• * Single magnetic nanoparticles can effectively generate directional scattered SPPs.
• * Particle size offers a broader tuning range for SPP directionality than permeability.
• * This work paves the way for efficient plasmonic devices and on-chip plasmonic circuits.