Asymptotics of surface-plasmon redshift saturation at subnanometric separations
File(s)PRB1.pdf (568.05 KB)
Accepted version
Author(s)
Schnitzer, O
Giannini, V
Craster, RV
Maier, SA
Type
Journal Article
Abstract
Many promising nanophotonics endeavors hinge upon the unique plasmonic properties of nanometallic structures with narrow nonmetallic gaps, which support superconcentrated bonding modes that singularly redshift with decreasing separations. In this Rapid Communication, we present a descriptive physical picture, complemented by elementary asymptotic formulas, of a nonlocal mechanism for plasmon redshift saturation at subnanometric gap widths. Thus, by considering the electron-charge and field distributions in the close vicinity of the metal-vacuum interface, we show that nonlocality is asymptotically manifested as an effective potential discontinuity. For bonding modes in the near-contact limit, the latter discontinuity is shown to be effectively equivalent to a widening of the gap. As a consequence, the resonance-frequency near-contact asymptotics are a renormalization of the corresponding local ones. Specifically, the renormalization furnishes an asymptotic plasmon-frequency lower bound that scales with the 1/4 power of the Fermi wavelength. We demonstrate these remarkable features in the prototypical cases of nanowire and nanosphere dimers, showing agreement between our elementary expressions and previously reported numerical computations.
Date Issued
2016-01-15
Date Acceptance
2015-12-29
Citation
Physical Review B, 2016, 93 (4)
ISSN
2469-9950
Publisher
American Physical Society
Journal / Book Title
Physical Review B
Volume
93
Issue
4
Copyright Statement
© 2016 The American Physical Society
Sponsor
Engineering & Physical Science Research Council (EPSRC)
The Leverhulme Trust
The Royal Society
Grant Number
EP/L024926/1
F/07 058/BK
WM110079
Subjects
Science & Technology
Technology
Physical Sciences
Materials Science, Multidisciplinary
Physics, Applied
Physics, Condensed Matter
Materials Science
Physics
OPTICAL-RESPONSE
QUANTUM
ENHANCEMENT
FIELD
NANOSTRUCTURES
NONLOCALITY
NANOSCALE
RESONANCE
MODES
physics.optics
physics.optics
cond-mat.mes-hall
Publication Status
Published
Article Number
041409(R)
Date Publish Online
2016-01-13