Scattering of nanowire surface plasmons coupled to quantum dots with azimuthal angle difference.

Po-Chen Kuo,Guang-Yin Chen,Yueh-Nan Chen

doi:10.1038/srep37766

Abstract

Coherent scatterings of surface plasmons coupled to quantun dots have attracted great attention in plasmonics. Recently, an experiment has shown that the quantum dots located nearby a nanowire can be separated not only in distance, but also an angle ϕ along the cylindrical direction. Here, by using the real-space Hamiltonian and the transfer matrix method, we analytically obtain the transmission/reflection spectra of nanowire surface plasmons coupled to quantum dots with an azimuthal angle difference. We find that the scattering spectra can show completely different features due to different positions and azimuthal angles of the quantum dots. When additionally coupling a cavity to the dots, we obtain the Fano-like line shape in the transmission and reflection spectra due to the interference between the localized and delocalized modes.

Highlights

Coherent scatterings of surface plasmons coupled to quantun dots have attracted great attention in plasmonics
Surface plasmons (SPs), or surface plasmon polaritons (SPPs), are propagating excitations of charge-density waves associated with the electromagnetic fields along the interface between a metal and a dielectric medium[1,2,3,4,5,6]
With the tunable luminescence properties, such as localized surface plasmon resonances (LSPRs)[24], plasmon-induced fluorescence enhancement[15], broad excitation spectra, narrow emission spectra, and size-dependent emission[25], quantum dot (QD) has recently attracted much attention for its ability to act as a photon detector[25] or being an excellent single photon source[26,27,28]

Summary

Results

Lets us consider two identical QDs near a cylindrical metal nanowire (dashed line) and reflection probabilities |r|2 (solid line) of the surface plasmon scattered by two QDs with azimuthal distance is angle diference as a function of detuning δ very small compared with the wavelength o≡f inE ck id−enωt0f.ieWldhse),nthde =tw 0o(hQerDes, it means the inter-dot are assumed to be at the same position. Ek − e xact ω0 is the forms of detuning between the incident SP energy with Ek and the QD the transmission and reflection amplitudes, t and r, are given exciton by energy ω0

By solving t

Discussion

Additional Information