Abstract
We report extensive numerical studies on plasmonic dimers of different configurations and find that their coupling effects can be categorized into three types of phenomena. First, like ordinary mechanical systems, the plasmonic dimers can exhibit positive couplings that show anti-crossing behavior. Second, they can also be arranged to exhibit negative couplings that display opposite trends in resonant frequency shifts. Third, when there are surface currents in proximity to each other, the resonance frequencies of the dimers exhibit unusual redshifts that do not have any analogies in conventional systems. Our work suggests that in addition to the well-known electric and magnetic dipolar interactions, contributions from the inductance of displacement currents in the near field cannot be ignored. Overall, asymmetric plasmonic dimers exhibit better sensitivities than the symmetric counterparts and our extensive studies also enable us to identify the plasmonic dimer with the highest sensing capabilities.
References
Feb 1, 1989·Physical Review A: General Physics·D F Bartlett, G Gengel
Jul 1, 1985·Physical Review Letters·D F Bartlett, T R Corle
Nov 10, 2005·Nano Letters·Björn M ReinhardJan Liphardt
Sep 15, 2006·The Journal of Physical Chemistry. B·Prashant K JainMostafa A El-Sayed
Oct 10, 2006·Physical Review Letters·O ArcizetL Rousseau
Feb 7, 2007·Physical Review Letters·H LiuX Zhang
Jan 31, 2008·Chemical Reviews·Matthew E StewartRalph G Nuzzo
May 24, 2008·Nature Materials·Jeffrey N AnkerRichard P Van Duyne
Sep 4, 2008·Physical Review Letters·Shuang ZhangXiang Zhang
Dec 19, 2008·The Journal of Physical Chemistry. a·Christopher TaborMostafa A El-Sayed
Mar 11, 2009·Nano Letters·Alison M FunstonPaul Mulvaney
Apr 16, 2009·Nano Letters·Prashant K Jain, Mostafa A El-Sayed
Dec 24, 2007·Optics Express·O L MuskensJ Gómez Rivas
Jul 8, 2009·Optics Express·T LiX Zhang
Jan 23, 2010·ACS Nano·Lisa V BrownNaomi J Halas
May 1, 2010·Science·Nikolay I Zheludev
Jun 12, 2010·Nano Letters·Sassan SheikholeslamiA Paul Alivisatos
Sep 28, 2010·Physical Review Letters·C MenzelF Lederer
Nov 6, 2010·Science·T KaelbererN I Zheludev
Jan 15, 2011·Physical Review Letters·Chih-Wei ChangXiang Zhang