7,040 research outputs found
Analytical results for a Bessel function times Legendre polynomials class integrals
When treating problems of vector diffraction in electromagnetic theory, the
evaluation of the integral involving Bessel and associated Legendre functions
is necessary. Here we present the analytical result for this integral that will
make unnecessary numerical quadrature techniques or localized approximations.
The solution is presented using the properties of the Bessel and associated
Legendre functions.Comment: 4 page
Optimized generation of spatial qudits by using a pure phase spatial light modulator
We present a method for preparing arbitrary pure states of spatial qudits,
namely, D-dimensional (D > 2) quantum systems carrying information in the
transverse momentum and position of single photons. For this purpose, a set of
D slits with complex transmission are displayed on a spatial light modulator
(SLM). In a recent work we have shown a method that requires a single
phase-only SLM to control independently the complex coefficients which define
the quantum state of dimension D. The amplitude information was codified by
introducing phase gratings inside each slit and the phase value of the complex
transmission was added to the phase gratings. After a spatial filtering process
we obtained in the image plane the desired qudit state. Although this method
has proven to be a good alternative to compact the previously reported
architectures, it presents some features that could be improved. In this paper
we present an alternative scheme to codify the required phase values that
minimizes the effects of temporal phase fluctuations associated to the SLM
where the codification is carried on. In this scheme the amplitudes are set by
appropriate phase gratings addressed at the SLM while the relative phases are
obtained by a lateral displacement of these phase gratings. We show that this
method improves the quality of the prepared state and provides very high
fidelities of preparation for any state. An additional advantage of this scheme
is that a complete 2\pi modulation is obtained by shifting the grating by one
period, and hence the encoding is not limited by the phase modulation range
achieved by the SLM. Numerical simulations, that take into account the phase
fluctuations, show high fidelities for thousands of qubit states covering the
whole Bloch sphere surface. Similar analysis are performed for qudits with D =
3 and D = 7.Comment: 12 pages, 7 figure
Metabolic diversity of diazotrophic bacteria isolates from Brazilian maize and sorghum cultivars by the biolog system.
Canonical transformation for stiff matter models in quantum cosmology
In the present work we consider Friedmann-Robertson-Walker models in the
presence of a stiff matter perfect fluid and a cosmological constant. We write
the superhamiltonian of these models using the Schutz's variational formalism.
We notice that the resulting superhamiltonians have terms that will lead to
factor ordering ambiguities when they are written as operators. In order to
remove these ambiguities, we introduce appropriate coordinate transformations
and prove that these transformations are canonical using the symplectic method.Comment: Revtex4 Class, 3 pages, No Figure
Noncommutative Metafluid Dynamics
In this paper we define a noncommutative (NC) Metafluid Dynamics
\cite{Marmanis}. We applied the Dirac's quantization to the Metafluid Dynamics
on NC spaces. First class constraints were found which are the same obtained in
\cite{BJP}. The gauge covariant quantization of the non-linear equations of
fields on noncommutative spaces were studied. We have found the extended
Hamiltonian which leads to equations of motion in the gauge covariant form. In
addition, we show that a particular transformation \cite{Djemai} on the usual
classical phase space (CPS) leads to the same results as of the
-deformation with . Besides, we will shown that an additional
term is introduced into the dissipative force due the NC geometry. This is an
interesting feature due to the NC nature induced into model.Comment: 11 page
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