5,724 research outputs found
Analytical Blowup Solutions to the Pressureless Navier-Stokes-Poisson Equations with Density-dependent Viscosity in R^N
We study the N-dimensional pressureless Navier--Stokes-Poisson equations with
density-dependent viscosity. With the extension of the blowup solutions for the
Euler-Poisson equations, the analytical blowup solutions,in radial symmetry, in
R^N are constructed.Comment: 12 Pages, more detail in the introduction to explain the validity of
the mode
Classical capacity of the lossy bosonic channel: the exact solution
The classical capacity of the lossy bosonic channel is calculated exactly. It
is shown that its Holevo information is not superadditive, and that a
coherent-state encoding achieves capacity. The capacity of far-field,
free-space optical communications is given as an example.Comment: 4 pages, 2 figures (revised version
Minimum-error discrimination between symmetric mixed quantum states
We provide a solution of finding optimal measurement strategy for
distinguishing between symmetric mixed quantum states. It is assumed that the
matrix elements of at least one of the symmetric quantum states are all real
and nonnegative in the basis of the eigenstates of the symmetry operator.Comment: 10 page
Operational Theory of Homodyne Detection
We discuss a balanced homodyne detection scheme with imperfect detectors in
the framework of the operational approach to quantum measurement. We show that
a realistic homodyne measurement is described by a family of operational
observables that depends on the experimental setup, rather than a single field
quadrature operator. We find an explicit form of this family, which fully
characterizes the experimental device and is independent of a specific state of
the measured system. We also derive operational homodyne observables for the
setup with a random phase, which has been recently applied in an ultrafast
measurement of the photon statistics of a pulsed diode laser. The operational
formulation directly gives the relation between the detected noise and the
intrinsic quantum fluctuations of the measured field. We demonstrate this on
two examples: the operational uncertainty relation for the field quadratures,
and the homodyne detection of suppressed fluctuations in photon statistics.Comment: 7 pages, REVTe
Maine Distributed Solar Valuation Study
During its 2014 session, the Maine Legislature enacted an Act to Support Solar Energy Development in Maine. P.L Chapter 562 (April 24, 2014) (codified at 35‐A M.R.S. §§ 3471‐3473) (“Act”). Section 1 of the Act contains the Legislative finding that it is in the public interest is to develop renewable energy resources, including solar energy, in a manner that protects and improves the health and well‐being of the citizens and natural environment of the State while also providing economic benefits to communities, ratepayers and the overall economy of the State.
Section 2 of the Act requires the Public Utilities Commission (Commission) to determine the value of distributed solar energy generation in the State, evaluate implementation options, and to deliver a report to the Legislature. To support this work, the Commission engaged a project team comprising Clean Power Research (Napa, California), Sustainable Energy Advantage (Framingham, Massachusetts), Pace Energy and Climate Center at the Pace Law School (White Plains, New York), and Dr. Richard Perez (Albany, New York).
Under the project, the team developed the methodology under a Commission‐run stakeholder review process, conducted a valuation on distributed solar for three utility territories, and developed a summary of implementation options for increasing deployment of distributed solar generation in the State.
The report includes three volumes which accompany this Executive Summary: Volume I Methodology; Volume II Valuation Results; Volume III Implementation Options
On the Relationship between Resolution Enhancement and Multiphoton Absorption Rate in Quantum Lithography
The proposal of quantum lithography [Boto et al., Phys. Rev. Lett. 85, 2733
(2000)] is studied via a rigorous formalism. It is shown that, contrary to Boto
et al.'s heuristic claim, the multiphoton absorption rate of a ``NOON'' quantum
state is actually lower than that of a classical state with otherwise identical
parameters. The proof-of-concept experiment of quantum lithography [D'Angelo et
al., Phys. Rev. Lett. 87, 013602 (2001)] is also analyzed in terms of the
proposed formalism, and the experiment is shown to have a reduced multiphoton
absorption rate in order to emulate quantum lithography accurately. Finally,
quantum lithography by the use of a jointly Gaussian quantum state of light is
investigated, in order to illustrate the trade-off between resolution
enhancement and multiphoton absorption rate.Comment: 14 pages, 7 figures, submitted, v2: rewritten in response to
referees' comments, v3: rewritten and extended, v4: accepted by Physical
Review
Readability of Instructional Materials and Usability of Online Learning Environment: Their Relations to the Development of Authentic and Contingent Knowledge
This research project correlates authentic knowledge with the readability of instructional materials and contingent knowledge with usability of the online learning environment. Based on thematic analyses in above two areas, we propose a model that governs how adult learners develop authentic and contingent knowledge in an intertwined manner
Multi-Dimensional Hermite Polynomials in Quantum Optics
We study a class of optical circuits with vacuum input states consisting of
Gaussian sources without coherent displacements such as down-converters and
squeezers, together with detectors and passive interferometry (beam-splitters,
polarisation rotations, phase-shifters etc.). We show that the outgoing state
leaving the optical circuit can be expressed in terms of so-called
multi-dimensional Hermite polynomials and give their recursion and
orthogonality relations. We show how quantum teleportation of photon
polarisation can be modelled using this description.Comment: 10 pages, submitted to J. Phys. A, removed spurious fil
Does nonlinear metrology offer improved resolution? Answers from quantum information theory
A number of authors have suggested that nonlinear interactions can enhance
resolution of phase shifts beyond the usual Heisenberg scaling of 1/n, where n
is a measure of resources such as the number of subsystems of the probe state
or the mean photon number of the probe state. These suggestions are based on
calculations of `local precision' for particular nonlinear schemes. However, we
show that there is no simple connection between the local precision and the
average estimation error for these schemes, leading to a scaling puzzle. This
puzzle is partially resolved by a careful analysis of iterative implementations
of the suggested nonlinear schemes. However, it is shown that the suggested
nonlinear schemes are still limited to an exponential scaling in \sqrt{n}.
(This scaling may be compared to the exponential scaling in n which is
achievable if multiple passes are allowed, even for linear schemes.) The
question of whether nonlinear schemes may have a scaling advantage in the
presence of loss is left open.
Our results are based on a new bound for average estimation error that
depends on (i) an entropic measure of the degree to which the probe state can
encode a reference phase value, called the G-asymmetry, and (ii) any prior
information about the phase shift. This bound is asymptotically stronger than
bounds based on the variance of the phase shift generator. The G-asymmetry is
also shown to directly bound the average information gained per estimate. Our
results hold for any prior distribution of the shift parameter, and generalise
to estimates of any shift generated by an operator with discrete eigenvalues.Comment: 8 page
Measuring the quantum statistics of an atom laser beam
We propose and analyse a scheme for measuring the quadrature statistics of an
atom laser beam using extant optical homodyning and Raman atom laser
techniques. Reversal of the normal Raman atom laser outcoupling scheme is used
to map the quantum statistics of an incoupled beam to an optical probe beam. A
multimode model of the spatial propagation dynamics shows that the Raman
incoupler gives a clear signal of de Broglie wave quadrature squeezing for both
pulsed and continuous inputs. Finally, we show that experimental realisations
of the scheme may be tested with existing methods via measurements of Glauber's
intensity correlation function.Comment: 4 pages, 3 figure
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