897 research outputs found
Whispering gallery modes in optical fibers based on reflectionless potentials
We consider an optical fiber with nanoscale variation of the effective fiber
radius supporting whispering gallery modes slowly propagating along the fiber,
and reveal that the radius variation can be designed to support reflectionless
propagation of these modes. We show that reflectionless modulations can realize
control of transmission amplitude and temporal delay, while enabling close
packing due to the absence of cross-talk, in contrast to conventional
potentials.Comment: 4 pages, 3 figure
Soliton dynamics in deformable nonlinear lattices
We describe wave propagation and soliton localization in photonic lattices
which are induced in a nonlinear medium by an optical interference pattern,
taking into account the inherent lattice deformations at the soliton location.
We obtain exact analytical solutions and identify the key factors defining
soliton mobility, including the effects of gap merging and lattice imbalance,
underlying the differences with discrete and gap solitons in conventional
photonic structures.Comment: 5 pages, 4 figure
Counting Statistics and Dephasing Transition in an Electronic Mach-Zehnder Interferometer
It was recently suggested that a novel type of phase transition may occur in
the visibility of electronic Mach-Zehnder Interferometers. Here, we present
experimental evidence for the existence of this transition. The transition is
induced by strongly non-Gaussian noise that originates from the strong coupling
of a quantum point contact to the interferometer. We provide a transparent
physical picture of the effect, by exploiting a close analogy to the
neutrino-oscillations of particle physics. In addition, our experiment
constitutes a probe of the singularity of the elusive full counting statistics
of a quantum point contact.Comment: 7 pages, 4 figures (+Supplement 8 pages, 9 figures
Stochastic dynamics of a Josephson junction threshold detector
We generalize the stochastic path integral formalism by considering
Hamiltonian dynamics in the presence of general Markovian noise. Kramers'
solution of the activation rate for escape over a barrier is generalized for
non-Gaussian driving noise in both the overdamped and underdamped limit. We
apply our general results to a Josephson junction detector measuring the
electron counting statistics of a mesoscopic conductor. Activation rate
dependence on the third current cumulant includes an additional term
originating from the back-action of the measurement circuit.Comment: 5 pages, 2 figures, discussion of experiment added, typos correcte
Bloch-mode analysis for retrieving effective parameters of metamaterials
We introduce a new approach for retrieving effective parameters of
metamaterials based on the Bloch-mode analysis of quasi-periodic composite
structures. We demonstrate that, in the case of single-mode propagation, a
complex effective refractive index can be assigned to the structure, being
restored by our method with a high accuracy. We employ both surface and volume
averaging of the electromagnetic fields of the dominating (fundamental) Bloch
modes to determine the Bloch and wave impedances, respectively. We discuss how
this method works for several characteristic examples, and demonstrate that
this approach can be useful for retrieval of both material and wave effective
parameters of a broad range of metamaterials.Comment: 12 pages, 10 figure
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