Bonding and Anti-bonding Modes of Plasmon Coupling Effects in TiO2-Ag Core-shell Dimers

Abstract

Bonding and anti-bonding modes of plasmon coupling effects are numerically investigated in TiO2-Ag core-shell nano dimers. First, splitting phenomena of the coupled anti-bonding modes are observed under the longitudinal polarization when the distance between the monomers decreases to a certain level. Second, one of the split resonance modes is identified to be formed by the dipole anti-bonding mode of the monomers from charge density distribution patterns. Those split modes have similar redshift behaviors as the coupled dipole bonding modes in the same situations. Furthermore, the intensities of those anti-bonding modes weaken with decreasing distance between the monomers, because of the interaction of the induced dipole moment in the monomers and the charge distribution variation on the facing surfaces of the gap by the coulomb attraction. Other split bands are the higher-order mode (octupole-like or triakontadipole-like), which do not have obvious peak-shift behavior, and the intensities have very little attenuation with decreasing distance. Finally, the coupling of the bonding and anti-bonding modes under the longitudinal polarization is symmetric (bonding).

Plasmonic Coupling Properties in Conductively Touched Metallic Ellipsoidal Dimer and Trimer

“…When two metallic nanoparticles are placed in close proximity, their individual dipolar Plasmonic Mode (PM) interact through either in-phase or out-of-phase couplings scenarios which result in excitation of bright and dark PMs [6,[19][20][21]. The local nearfield in the gap region is significantly enhanced and therefore can be considered as hot spots for surface Raman spectroscopy [3][4][5]22].…”

Theoretical calculation of the optical absorption property of nanoparticles composed of an Au Core and Si shell embedded in silica

“…The discrete-dipole approximation (DDA) method that accounts for optical dipole-dipole coupling between particles was utilized to explain these results. Both single [13,14] and multiple core-shell nanoparticles [15,16] have been theoretically investigated by DDA calculations. This study will contribute to a better understanding of the optical absorption property that should be obtained from fabrication of Au@Si core-shell bifunctional nanostructures for use in the emerging fields of nanophotonics, sensing and associated applications.…”

Plasmonic plano-semi-cylindrical nanocavities with high-efficiency local-field confinement

“…Localized surface plasmon resonance (LSPR) as a result of collective oscillation of free electrons in noble metals have been investigated extensively either in single nanostructures1234 or in hybrid systems like dimmers, oligomers, core-shells, particle-film systems, and etc 5678910111213141516171819202122232425262728…”

“…Furthermore, such a MIM system has been incorporated into the bow-tie nanoantennas and much enhanced local field may be achieved in the extremely small gap20. Bonding and antibonding plasmonic resonance modes are also typical features of the hybrid systems22232425262728, which have been observed in metallic nanoshells provided by nanorings2223, nanocups24, and the silica-gold core-shell nanoparticles25.…”