2,840 research outputs found
Optimization of periodic single-photon sources based on combined multiplexing
We consider periodic single-photon sources with combined multiplexing in
which the outputs of several time-multiplexed sources are spatially
multiplexed. We give a full statistical description of such systems in order to
optimize them with respect to maximal single-photon probability. We carry out
the optimization for a particular scenario which can be realized in bulk optics
and its expected performance is potentially the best at the present state of
the art. We find that combined multiplexing outperforms purely spatially or
time multiplexed sources for certain parameters only, and we characterize these
cases. Combined multiplexing can have the advantages of possibly using less
nonlinear sources, achieving higher repetition rates, and the potential
applicability for continuous pumping. We estimate an achievable single-photon
probability between 85% and 89%.Comment: 11 pages, 6 figur
On convergence properties of infinitesimal generators of scaled multi-type CBI processes
It is a common method for proving weak convergence of a sequence of
time-homogeneous Markov processes towards a time-homogeneous Markov process
first to show convergence of the corresponding infinitesimal generators and
then to check some additional conditions. The aim of the present paper is to
investigate convergence properties of discrete infinitesimal generators of
appropriately scaled random step functions formed from a multi-type continuous
state and continuous time branching process with immigration. We also present a
convergence result for usual infinitesimal generators of the branching
processes in question appropriately normalized.Comment: 17 pages. Title is changed, and new parts (e.g., Corollary 3.5 and
Remark 3.6) are added. In Section 2 we recall some notions and statements
from arXiv:1403.0245 and arXiv:1404.224
Fourier transform of a Gaussian measure on the Heisenberg group
An explicit formula is derived for the Fourier transform of a Gaussian
measure on the Heisenberg group at the Schrodinger representation. Using this
explicit formula, necessary and sufficient conditions are given for the
convolution of two Gaussian measures to be a Gaussian measure.Comment: 38 pages, completed versio
Entropy production in diffusion-reaction systems: The reactive random Lorentz gas
We report the study of a random Lorentz gas with a reaction of isomerization
between the two colors of moving particles elastically
bouncing on hard disks. The reaction occurs when the moving particles collide
on catalytic disks which constitute a fraction of all the disks. Under the
dilute-gas conditions, the reaction-diffusion process is ruled by two coupled
Boltzmann-Lorentz equations for the distribution functions of the colors. The
macroscopic reaction-diffusion equations with cross-diffusion terms induced by
the chemical reaction are derived from the kinetic equations. We use a
-theorem of the kinetic theory in order to derive a macroscopic entropy
depending on the gradients of color densities and which has a non-negative
entropy production in agreement with the second law of thermodynamics.Comment: 14 pages, 3 eps-figure
Photon number conservation and photon interference
The group theoretical aspect of the description of passive lossless optical
four-ports (beam splitters) is revisited. It is shown through an example, that
this approach can be useful in understanding interferometric schemes where a
low number of photons interfere. The formalism is extended to passive lossless
optical six-ports, their SU(3)-theory is outlined.Comment: Contribution at "Classical and Quantum Interference" workshop in RCO,
Olomouc, Oct. 25-26 2001. A corrected versio
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