690 research outputs found
Quantum Erasure by Transverse Indistinguishability
We show that the first experiment with double-slits and twin photons detected
in coincidence can be understood as a quantum eraser. The ``which path''
information is erased by transverse indistinguishability obtained by means of
mode filtering in the twin conjugated beam. A delayed choice quantum eraser
based on the same scheme is proposed.Comment: Submitted for publication in Optics Communication
Image and Coherence Transfer in the Stimulated Down-conversion Process
The intensity transverse profile of the light produced in the process of
stimulated down-conversion is derived. A quantum-mechanical treatment is used.
We show that the angular spectrum of the pump laser can be transferred to the
stimulated down-converted beam, so that images can also be transferred from the
pump to the down-converted beam. We also show that the transfer can occur from
the stimulating beam to the down-converted one. Finally, we study the process
of diffraction through an arbitrarily shaped screen. For the special case of a
double-slit, the interference pattern is explicitly obtained. The visibility
for the spontaneous emitted light is in accordance with the van Cittert -
Zernike theorem for incoherent light, while the visibility for the stimulated
emitted light is unity. The overall visibility is in accordance with previous
experimental results
Trastuzumab-Induced Myocardiotoxicity Mimicking Acute Coronary Syndrome
Trastuzumab is an important biological agent in the treatment of HER2-positive breast cancer, with effects on response rates, progression-free survival, overall survival and quality of life. Although this drug is well tolerated in terms of adverse effects, trastuzumab-associated myocardiotoxicity has been described to have an incidence of 0.6–4.5% and in rare cases, the drug can trigger severe congestive heart failure with progression to death or even mimic acute coronary syndrome with complete left bundle branch blockade. In this paper is reported a case of trastuzumab-associated myocardiotoxicity manifesting as acute coronary syndrome in a 69-year-old female. The patient is currently undergoing a conservative clinical treatment that restricts overexertion
Spatial antibunching of photons with parametric down-conversion
The theoretical framework behind a recent experiment by Nogueira et. al.
[Phys. Rev. Lett. 86}, 4009 (2001)] of spatial antibunching in a two-photon
state generated by collinear type II parametric down-conversion and a
birefringent double-slit is presented. The fourth-order quantum correlation
function is evaluated and shown to violate the classical Schwarz-type
inequality, ensuring that the field does not have a classical analog. We expect
these results to be useful in the rapidly growing fields of quantum imaging and
quantum information.Comment: 5 pages, 3 figures. Minor changes made, accepted for publication in
PR
Generation of spatial antibunching with free propagating twin beams
We propose and implement a novel method to produce a spatial anti-bunched
field with free propagating twin beams from spontaneous parametric
down-conversion. The method consists in changing the spatial propagation by
manipulating the transverse degrees of freedom through reflections of one of
the twin beams. Our method use reflective elements eliminating losses from
absorption by the objects inserted in the beams.Comment: Submitted for publication in Phys. Rev.
Parasitoides de Ornidia obesa Fabricius (Diptera: Syrphidae) coletados em fezes de galinha no Brasil
Quantum walks: a comprehensive review
Quantum walks, the quantum mechanical counterpart of classical random walks,
is an advanced tool for building quantum algorithms that has been recently
shown to constitute a universal model of quantum computation. Quantum walks is
now a solid field of research of quantum computation full of exciting open
problems for physicists, computer scientists, mathematicians and engineers.
In this paper we review theoretical advances on the foundations of both
discrete- and continuous-time quantum walks, together with the role that
randomness plays in quantum walks, the connections between the mathematical
models of coined discrete quantum walks and continuous quantum walks, the
quantumness of quantum walks, a summary of papers published on discrete quantum
walks and entanglement as well as a succinct review of experimental proposals
and realizations of discrete-time quantum walks. Furthermore, we have reviewed
several algorithms based on both discrete- and continuous-time quantum walks as
well as a most important result: the computational universality of both
continuous- and discrete- time quantum walks.Comment: Paper accepted for publication in Quantum Information Processing
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