2,254 research outputs found
Nonlocal study of ultimate plasmon hybridization
Within our recently proposed generalized nonlocal optical response (GNOR)
model, we revisit the fundamental problem of an optically excited plasmonic
dimer. The dimer consists of two identical cylinders separated by a
nanometre-sized gap. We consider the transition from separated dimers via
touching dimers to finally overlapping dimers. In particular, we focus on the
touching case, showing a fundamental limit on the hybridization of the bonding
plasmon modes due to nonlocality. Using transformation optics we determine a
simple analytical equation for the resonance energies of the bonding plasmon
modes of the touching dimer
Generalized nonlocal optical response in nanoplasmonics
Metallic nanostructures exhibit a multitude of optical resonances associated
with localized surface plasmon excitations. Recent observations of plasmonic
phenomena at the sub-nanometer to atomic scale have stimulated the development
of various sophisticated theoretical approaches for their description. Here
instead we present a comparatively simple semiclassical generalized nonlocal
optical response (GNOR) theory that unifies quantum-pressure convection effects
and induced-charge diffusion kinetics, with a concomitant complex-valued GNOR
parameter. Our theory explains surprisingly well both the frequency shifts and
size-dependent damping in individual metallic nanoparticles (MNPs) as well as
the observed broadening of the cross-over regime from bonding-dipole plasmons
to charge-transfer plasmons in MNP dimers, thus unraveling a classical
broadening mechanism that even dominates the widely anticipated
short-circuiting by quantum tunneling. We anticipate that the GNOR theory can
be successfully applied in plasmonics to a wide class of conducting media,
including doped semiconductors and low-dimensional materials such as graphene.Comment: 7 pages, including 3 figures. Supplementary information is available
upon request to author
Interplay of nonlocal response, damping, and low group velocity in surface-plasmon polaritons
Nanoplasmonics beyond Ohm's law
In tiny metallic nanostructures, quantum confinement and nonlocal response
change the collective plasmonic behavior with important consequences for e.g.
field-enhancement and extinction cross sections. We report on our most recent
developments of a real-space formulation of an equation-of-motion that goes
beyond the common local-response approximation and use of Ohm's law as the
central constitutive equation. The electron gas is treated within a
semi-classical hydrodynamic model with the emergence of a new intrinsic length
scale. We briefly review the new governing wave equations and give examples of
applying the nonlocal framework to calculation of extinction cross sections and
field enhancement in isolated particles, dimers, and corrugated surfaces.Comment: Invited paper for TaCoNa-Photonics 2012 (www.tacona-photonics.org),
to appear in AIP Conf. Pro
What does a primary care annual review for RA include? A national GP survey
Letter to the edito
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