Landau Damping in Hybrid Plasmonics

Area of Science:

• Plasmonics
• Nanomaterials Science
• Quantum Mechanics

Background:

• Localized surface plasmons (LSPs) are collective electron oscillations on metal nanoparticle surfaces.
• Landau damping (LD) is a key mechanism for LSP decay, converting plasmon energy into electron-hole pairs.
• Hybrid nanostructures (metal core/dielectric shell) offer tunable optical properties.

Purpose of the Study:

• Investigate the Landau damping (LD) mechanism in hybrid nanoplasmonic structures.
• Determine the influence of dielectric shell properties (permittivity, electron effective mass) on LD.
• Identify strategies to enhance LD and hot carrier generation.

Main Methods:

• Theoretical analysis of Landau damping in metal core/dielectric shell nanostructures.
• Modeling electron spillover and quasi-discrete energy levels in the dielectric shell.
• Investigating transition absorption at the metal-dielectric interface.

Main Results:

• Landau damping in hybrid structures is significantly influenced by the dielectric shell's permittivity and electron effective mass.
• LD strength can be enhanced by up to an order of magnitude.
• Electron spillover into the dielectric and quasi-discrete energy levels are identified as key contributing factors.
• Transition absorption at the metal-dielectric interface is a dominant contribution to LD.

Conclusions:

• Dielectric shell properties critically control Landau damping in hybrid nanoplasmonics.
• Enhanced LD and hot carrier production are achievable through judicious material and thickness selection.
• These findings enable engineering of decay rates for applications in photodetection and photochemistry.