Molding of Plasmonic Resonances in Metallic Nanostructures: Dependence of the Non-Linear Electric Permittivity on System Size and Temperature

Abstract

In this paper, we review the principal theoretical models through which the dielectric function of metals can be described. Starting from the Drude assumptions for intraband transitions, we show how this model can be improved by including interband absorption and temperature effect in the damping coefficients. Electronic scattering processes are described and included in the dielectric function, showing their role in determining plasmon lifetime at resonance. Relationships among permittivity, electric conductivity and refractive index are examined. Finally, a temperature dependent permittivity model is presented and is employed to predict temperature and non-linear field intensity dependence on commonly used plasmonic geometries, such as nanospheres.

Experimental Route to Scanning Probe Hot‐Electron Nanoscopy (HENs) Applied to 2D Material

“…[30,31] However, a rigorous solution of the matching problem is not trivial, since the SPP K z in the grating region has a dependence on all the grating parameters, including P.…”

Replacing noble metals with alternative metals in MID-IR frequency: A theoretical approach

“…The results indicating that the loss factor is less salient at higher thicknesses. It is clearly visible that for all metals the minor losses are with a thickness of 55 nm [13]. …”

“…When the grain size is large, the relaxation rate is given by 0 Γ (it is the relaxation constant of the bulk material). When the grain size is small, as in the case of thin metal films, equation 20 describes additional grain-boundary scattering [13]:…”

“…10, we have investigated through numerical simulations the dependence of the permittivity of all metals from their thickness. The strong dependence of thickness in permittivity is ascribed to the thickness-dependent damping factor d Γ (see equation (20)) [13].…”

The magic of nanoplasmonics: from superhydrophobic and 3D suspended devices for SERS/TERS-like applications to hot-electrons based nanoscopy

“…SPs are bounded mode decaying from the interface in both media (metal and surrounding dielectric) losing energy along the propagation. The energy loss is scattered in the environment as radiation by means of photons (surface roughness, tip-end emission) and into the metal in a multiple step process which involves photon-electron (ph-e), electron-electron (e-e) and electronphonon (e-p) interactions [26]. While e-e and e-p scattering processes eventually lead to power dissipation and consequent heating of the structure, ph-e interaction produces, at first, electron-hole pairs and thus "hot"-electrons [9].…”