397 research outputs found
Polarization entangled state measurement on a chip
The emerging strategy to overcome the limitations of bulk quantum optics
consists of taking advantage of the robustness and compactness achievable by
the integrated waveguide technology. Here we report the realization of a
directional coupler, fabricated by femtosecond laser waveguide writing, acting
as an integrated beam splitter able to support polarization encoded qubits.
This maskless and single step technique allows to realize circular transverse
waveguide profiles able to support the propagation of Gaussian modes with any
polarization state. Using this device, we demonstrate the quantum interference
with polarization entangled states and singlet state projection.Comment: Revtex, 5+2 pages (with supplementary information), 4+1 figure
Experimental test of the no signaling theorem
In 1981 N. Herbert proposed a gedanken experiment in order to achieve by the
''First Laser Amplified Superluminal Hookup'' (FLASH) a faster than light
communication (FTL) by quantum nonlocality. The present work reports the first
experimental realization of that proposal by the optical parametric
amplification of a single photon belonging to an entangled EPR pair into an
output field involving 5 x 10^3 photons. A thorough theoretical and
experimental analysis explains in general and conclusive terms the precise
reasons for the failure of the FLASH program as well as of any similar FTL
proposals.Comment: 4 pages, 4 figure
Hyperbolic Kac-Moody superalgebras
We present a classification of the hyperbolic Kac-Moody (HKM) superalgebras.
The HKM superalgebras of rank larger or equal than 3 are finite in number (213)
and limited in rank (6). The Dynkin-Kac diagrams and the corresponding simple
root systems are determined. We also discuss a class of singular
sub(super)algebras obtained by a folding procedure
Metals distribution in the organic and inorganic fractions of soil: a case study on soils from Sicily
AbstractThe content of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn, has been determined in the organic and inorganic fraction of eight soil samples from Sicily. A modified type-Tessier sequential extraction procedure has been used to recognize metals in five different fractions categorised as follows: (a) exchangeable metals, (b) metals bound to carbonates, (c) metals bound to iron and manganese oxides, (d) metals bound to organic matter, and (e) metals in residual fraction. The mineralogical composition of soils samples was characterized by X-ray diffraction. Humic substances were extracted by means of an alkaline extraction procedure. It has been found that both the mineralogical composition and the different content of humic fraction of organic matter in the soils investigated are responsible for the observed trace metal distribution. The obtained data show that a significant amount of trace metals is bound to the organic fraction where different binding sites are present simultaneously. In particular, Pb an..
N=2 supersymmetric extension of the Tremblay-Turbiner-Winternitz Hamiltonians on a plane
The family of Tremblay-Turbiner-Winternitz Hamiltonians on a plane,
corresponding to any positive real value of , is shown to admit a supersymmetric extension of the same kind as that introduced by Freedman
and Mende for the Calogero problem and based on an superalgebra. The irreducible representations of the latter
are characterized by the quantum number specifying the eigenvalues of the first
integral of motion of . Bases for them are explicitly constructed.
The ground state of each supersymmetrized Hamiltonian is shown to belong to an
atypical lowest-weight state irreducible representation.Comment: 18 pages, no figur
The Origin of Separable States and Separability Criteria from Entanglement-breaking Channels
In this paper, we show that an arbitrary separable state can be the output of
a certain entanglement-breaking channel corresponding exactly to the input of a
maximally entangled state. A necessary and sufficient separability criterion
and some sufficient separability criteria from entanglement-breaking channels
are given.Comment: EBCs with trace-preserving and EBCs without trace-preserving are
separately discusse
Nonlinear Evolution Equations Invariant Under Schroedinger Group in three-dimensional Space-time
A classification of all possible realizations of the Galilei,
Galilei-similitude and Schroedinger Lie algebras in three-dimensional
space-time in terms of vector fields under the action of the group of local
diffeomorphisms of the space \R^3\times\C is presented. Using this result a
variety of general second order evolution equations invariant under the
corresponding groups are constructed and their physical significance are
discussed
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