TY - JOUR

T1 - Curve crossing and negative refraction in simulations of near-field coupled metallic nanoparticle arrays

AU - Lopata, Kenneth

AU - Neuhauser, Daniel

AU - Baer, Roi

N1 - Funding Information:
This research was supported by the NSF and PRF.

PY - 2007

Y1 - 2007

N2 - We extend our previous results [R. Baer, J. Chem. Phys. 126, 014705 (2007).] to develop a simple theory of localized surface plasmon-polariton (LSPP) dispersion on regular arrays of metal nanoparticles in the weak-field and weak-damping limits. This theory describes the energy-momentum as well as the polarization-momentum properties of LSPP waves, both of which are crucial to plasmonic device design. We then explicitly compute the dispersion relation for isotropic and anisotropic two-dimensional square lattices, and show curve crossings between all three levels as well as negative refraction where the phase and group velocities (refractive indices), or at least their projection along the main axis, have different signs. The curve crossing implies that scattering between the different polarizations, and therefore different velocities, is easy at the curve crossing momenta, so that a quick change in wave packet direction can be achieved. Time-resolved wave packet dynamics simulations demonstrate negative refraction and the easy scattering over nanometer length scales. This paper also gives some computational schemes for future applications, such as a way to include source terms and how to efficiently treat dissipative effects.

AB - We extend our previous results [R. Baer, J. Chem. Phys. 126, 014705 (2007).] to develop a simple theory of localized surface plasmon-polariton (LSPP) dispersion on regular arrays of metal nanoparticles in the weak-field and weak-damping limits. This theory describes the energy-momentum as well as the polarization-momentum properties of LSPP waves, both of which are crucial to plasmonic device design. We then explicitly compute the dispersion relation for isotropic and anisotropic two-dimensional square lattices, and show curve crossings between all three levels as well as negative refraction where the phase and group velocities (refractive indices), or at least their projection along the main axis, have different signs. The curve crossing implies that scattering between the different polarizations, and therefore different velocities, is easy at the curve crossing momenta, so that a quick change in wave packet direction can be achieved. Time-resolved wave packet dynamics simulations demonstrate negative refraction and the easy scattering over nanometer length scales. This paper also gives some computational schemes for future applications, such as a way to include source terms and how to efficiently treat dissipative effects.

UR - http://www.scopus.com/inward/record.url?scp=39349088530&partnerID=8YFLogxK

U2 - 10.1063/1.2796162

DO - 10.1063/1.2796162

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AN - SCOPUS:39349088530

SN - 0021-9606

VL - 127

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

IS - 15

M1 - 154714

ER -