Control of the stability and soliton formation of dipole moments in a nonlinear plasmonic finite nanoparticle array

Abstract

We perform numerical analysis of a finite nanoparticle array, in which the transversal dipolar polarizations are excited by a homogenous optical field. Considering the linearly long-range dipole-dipole interaction and the cubic dipole nonlinearity of particle, the characteristics of stability of a finite number nanoparticle array should be revised, compared with that of an infinite number nanoparticle array. A critical point in the low branch of the bistable curve is found, beyond which the low branch becomes unstable for a finite number of nanoparticles. The influence of the external field intensities and detuning frequencies on this critical point are investigated in detail. When the total number of particles approaches infinity, our results become similar to that of an infinity number particle system [32]. Notably, with appropriate external optical field, a dark dipole soliton is formed. Moreover, when the scaled detuning is set to an appropriate value, a double monopole dark soliton (DMDS) consisting of two particles is formed. The DMDS may have potential applications in the subwavelength highly precise detection because of its very small width.

Anderson localization in metallic nanoparticle arrays

“…In the simulations, the varying range of the external driving fields that are imposed on the 100-particle system is set as |E 0 | 2 = 0.45 × 10 −4 ∼ 1.35 × 10 −4 . It was demonstrated that the induced dipole intensity relies on the intensity of the driving field [18]. Therefore, for a random electrical driving field, the induced dipole intensity of each particle is different from that induced from other particles.…”

“…We previously demonstrated that [18], using a homogeneous electrically driving field, a dipole kink could be formed when two adjacent particles' dipole intensities were initially located at the low and top branches with respect to the bistable curve. Localized dipole modes could also be formed when two kinks were created in the nanoparticle arrays.…”

“…Localized dipole modes could also be formed when two kinks were created in the nanoparticle arrays. As the intensity of the external field (|E 0 | 2 ) is increased beyond the threshold, the kink begins to move, leading to the dipole intensity (|P v| 2 ) jumping from the low branch to the top branch, thereby breaking the stability of the dipole mode [18].…”