Lifetime of the first and second collective excitations in metallic nanoparticles

Abstract

We determine the lifetime of the surface plasmon in metallic nanoparticles under various conditions, concentrating on the Landau damping, which is the dominant mechanism for intermediate-size particles. Besides the main contribution to the lifetime, which smoothly increases with the size of the particle, our semiclassical evaluation yields an additional oscillating component. For the case of noble metal particles embedded in a dielectric medium, it is crucial to consider the details of the electronic confinement; we show that in this case the lifetime is determined by the shape of the self-consistent potential near the surface. Strong enough perturbations may lead to the second collective excitation of the electronic system. We study its lifetime, which is limited by two decay channels: Landau damping and ionization. We determine the size dependence of both contributions and show that the second collective excitation remains as a well-defined resonance.

Resonance plasmon linewidth oscillations in spheroidal metallic nanoparticle embedded in a dielectric matrix

“…21 Our result for the Na nanoparticles mainly agrees with a similar results obtained in Refs. 29,30. Experiments on alkaline clusters with a diameter in the range of 10−50Å in vacuum 13 yield a linewidth of the order of Γ ∼ 1 eV.…”

“…provided that ω ≫ ν s ≫ ν, and (30) provided that ω ≫ ν s and ν s ≪ ν. The factors L and L ⊥ in Eqs.…”

“…The damping of surface plasmon resonances in MNs has been well studied both experimentally [12][13][14][15][16][17][18][19][20][21][22][23][24] and theoretically [25][26][27][28][29][30][31][32][33] . Usually, both the bulk and the surface damping mechanisms play an important role in the * email: ngrigor@bitp.kiev.ua surface plasmon decay.…”

“…Within the framework of the kinetic approach, we found that the the surface plasmon linewidth exhibits the oscillations as a function of the nanoparticle size, shape, and light frequency. We will demonstrate how they correspond to the oscillations detected earlier [28][29][30][31] in numerical calculations based on the time dependent local density approximation.…”

Landau damping of surface plasmons in metal nanostructures

“…Surface-assisted plasmon decay (Landau damping) has been extensively studied experimentally [33][34][35][36][37][38][39][40][41][42][43] and theoretically [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59] since the pioneering paper by Kawabata and Kubo [44], who have shown that, for a spherical particle of radius a, the surface scattering rate is γ sp = 3v F /4a, where v F is the electron Fermi velocity. In subsequent quantum-mechanical studies carried within random phase approximation (RPA) [45][46][47][48][49][50][51] and timedependent local density approximation (TDLDA) [52][53][54][55][56][57][58][59] approaches, a more complicated picture has emerged involving the role of confining potential and nonlocal effects.…”