384 research outputs found
Approach to first-order exact solutions of the Ablowitz-Ladik equation
We derive exact solutions of the Ablowitz-Ladik (A-L) equation using a special ansatz that linearly relates the real and imaginary parts of the complex function. This ansatz allows us to derive a family of first-order solutions of the A-L equation with two independent parameters. This novel technique shows that every exact solution of the A-L equation has a direct analog among first-order solutions of the nonlinear Schrödinger equation (NLSE).Two of the authors (A.A. and N.A.) acknowledge the
support of the Australian Research Council (Discovery Project
No. DP0985394). N.A. is a grateful recipient of support from
the Alexander von Humboldt Foundation (Germany)
Bloch cavity solitons in nonlinear resonators with intracavity photonic crystals
We predict a novel type of cavity solitons, Bloch cavity solitons, existing in nonlinear resonators with
the refractive index modulated in both longitudinal and transverse directions and for both focusing (at
normal diffraction) and defocusing (at anomalous diffraction) nonlinearities. We develop a modified
mean-field theory and analyze the properties of these novel cavity solitons demonstrating, in particular,
their substantial narrowing in the zero-diffraction regime
Coupling between a dark and a bright eigenmode in a terahertz metamaterial
Terahertz time domain spectroscopy and rigorous simulations are used to probe
the coupling between a dark and a bright plasmonic eigenmode in a metamaterial
with broken symmetry. The metamaterial consists of two closely spaced split
ring resonators that have their gaps in non-identical positions within the
ring. For normal incidence and a fixed polarization both lowest order
eigenmodes of the split ring resonators can be excited; although one of them
has to be regarded as dark since coupling is prohibited because of symmetry
constraints. Emphasis in this work is put on a systematic evaluation of the
coupling effects depending on a spectral tuning of both resonances
Manipulating the Interaction between Localized and Delocalized Surface Plasmon Polaritons in Graphene
The excitation of localized or delocalized surface plasmon polaritons in
nanostructured or extended graphene has attracted a steadily increasing
attention due to their promising applications in sensors, switches, and
filters. These single resonances may couple and intriguing spectral signatures
can be achieved by exploiting the entailing hybridization. Whereas thus far
only the coupling between localized or delocalized surface plasmon polaritons
has been studied in graphene nanostructures, we consider here the interaction
between a localized and a delocalized surface plasmon polariton. This
interaction can be achieved by two different schemes that reside on either
evanescent near- field coupling or far-field interference. All observable
phenomena are corroborated by analytical considerations, providing insight into
the physics and paving the way for compact and tunable optical components at
infrared and terahertz frequencies.Comment: 6 pages, 4 figure
Dissipation-driven entanglement between qubits mediated by plasmonic nanoantennas
A novel scheme is proposed to generate a maximally entangled state between
two qubits by means of a dissipation-driven process. To this end, we entangle
the quantum states of qubits that are mutually coupled by a plasmonic
nanoantenna. Upon enforcing a weak spectral asymmetry in the properties of the
qubits, the steady-state probability to obtain a maximally entangled,
subradiant state approaches unity. This occurs despite the high losses
associated to the plasmonic nanoantenna that are usually considered as being
detrimental. The entanglement scheme is shown to be quite robust against
variations in the transition frequencies of the quantum dots and deviations in
their prescribed position with respect to the nanoantenna. Our work paves the
way for novel applications in the field of quantum computation in highly
integrated optical circuits.Comment: 9 pages, 5 figure
An advanced Jones calculus for the classification of periodic metamaterials
By relying on an advanced Jones calculus we analyze the polarization
properties of light upon propagation through metamaterial slabs in a
comprehensive manner. Based on symmetry considerations, we show that all
periodic metamaterials may be divided into five different classes only. It is
shown that each class differently affects the polarization of the transmitted
light and sustains different eigenmodes. We show how to deduce these five
classes from symmetry considerations and provide a simple algorithm that can be
applied to decide by measuring transmitted intensities to which class a given
metamaterial is belonging to only
Towards negative index self-assembled metamaterials
We investigate the magnetic response of meta-atoms that can be fabricated by
a bottom-up technique. Usually such meta-atoms consist of a dielectric core
surrounded by a large number of solid metallic nanoparticles. In contrast to
those meta-atoms considered thus far, we study here for the first time hollow
metallic nanoparticles (shells). In doing so we solve one of the most pertinent
problems of current self-assembled metamaterials, namely implementing
meta-atoms with sufficiently large resonance strength and small absorption.
Both conditions have to be met for deep sub-wavelength meta-atoms to obtain
effectively homogeneous metamaterials which may be meaningfully described by
negative material parameters. Eventually we show that by using these findings
self-assembled negative index materials come in reach.Comment: 15 pages, 5 Figures, Published in PR
Nanoantennas for ultrabright single photon sources
We propose to use nanoantennas coupled to incoherently pumped quantum dots
for ultra-bright single photon emission. Besides fully quantum calculations, we
analyze an analytical expression for the emitted photon rate. From these
analytical considerations it turns out that the Purcell factor and the pumping
rate are the main quantities of interest. We also disclose a trade-off between
the emitted photon rate and the nonclassical nature of the emitted light. This
trade-off has to be considered while designing suitable nanoantennas, which we
also discuss in depth
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