315 research outputs found
Time domain Einstein-Podolsky-Rosen correlation
We experimentally demonstrate creation and characterization of
Einstein-Podolsky-Rosen (EPR) correlation between optical beams in the time
domain. The correlated beams are created with two independent continuous-wave
optical parametric oscillators and a half beam splitter. We define temporal
modes using a square temporal filter with duration and make time-resolved
measurement on the generated state. We observe the correlations between the
relevant conjugate variables in time domain which correspond to the EPR
correlation. Our scheme is extendable to continuous variable quantum
teleportation of a non-Gaussian state defined in the time domain such as a
Schr\"odinger cat-like state.Comment: 4 pages, 4 figure
Quantum mode filtering of non-Gaussian states for teleportation-based quantum information processing
We propose and demonstrate an effective mode-filtering technique of
non-Gaussian states generated by photon-subtraction. More robust non-Gaussian
states have been obtained by removing noisy low frequencies from the original
mode spectrum. We show that non-Gaussian states preserve their non-classicality
after quantum teleportation to a higher degree, when they have been
mode-filtered. This is indicated by a stronger negativity of
the Wigner function at the origin, compared to for states
that have not been mode-filtered. This technique can be straightforwardly
applied to various kinds of photon-subtraction protocols, and can be a key
ingredient in a variety of applications of non-Gaussian states, especially
teleportation-based protocols towards universal quantum information processing
Quantum teleportation of non-classical wave-packets, an effective multimode theory
We develop a simple and efficient theoretical model to understand the quantum
properties of broadband continuous variable quantum teleportation. We show
that, if stated properly, the problem of multimode teleportation can be
simplified to teleportation of a single effective mode that describes the input
state temporal characteristic. Using that model, we show how the finite
bandwidth of squeezing and external noise in the classical channel affect the
output teleported quantum field. We choose an approach that is especially
relevant for the case of non-Gaussian non-classical quantum states and we
finally back-test our model with recent experimental results.Comment: Many typos corrected, some mistakes in the reference section
correcte
Model for neutrino mixing based on SO(10)
Assuming grand unified theory (GUT) and supersymmetry, we propose a simple
model which can consistently accommodate the masses and mixings for quarks and
leptons. The grand unified group is SO(10), and , , and representations are introduced for the Higgs superfields which give
masses to the quarks and leptons. The differences of masses and mixings between
the quarks and the leptons are attributed to the Higgs boson structure. Below
the GUT energy scale, the model is the same as the minimal supersymmetric
standard model except its inclusion of dimension-5 operators for the small
neutrino masses. The renormalization group equations of the independent
parameters for the Higgs couplings with the quarks and leptons are given
explicitly to connect the two energy scales of GUT and electroweak theory.Comment: 17 pages, 2 figure
The RR Lyrae variables and Horizontal Branch of NGC6656 (M22)
The first calibrated broadband UBVI time-series photometry is presented for
the RR Lyrae variable stars in NGC6656 (M22), with observations spanning a
range of twenty-two years. We have also redetermined the variability types and
periods for the RR Lyrae stars identified previously by photographic
observations, revising the number of fundamental-mode RR Lyrae variables (RR0)
to 10 and the number of first-overtone variables (RR1) to 16. The mean periods
of the RR0 and RR1 variables are _{RR0}=0.66 \pm 0.02 d and _{RR1}=0.33
\pm 0.01 d, respectively, supporting an Oosterhoff II classification for the
cluster. The number ratio of RR1- to all RR-type variables is N_1/N_{RR}=0.61,
also consistent with an Oosterhoff II designation. Both the RR Lyrae stars'
minimum light colors and the blue edge of the RR Lyrae instability strip
suggest E(B-V)=0.36 \pm 0.02 mag toward M22. Regarding the HB morphology of
M22, we find (B-R)/(B+V+R)=+0.97 \pm 0.1 and at least one "gap" located in an
unusual part of the blue HB, in the middle of the so-called hot HB stars.Comment: accepted to A
A New Hardware Correlator in Korea: Performance Evaluation using KVN observations
We report results of the performance evaluation of a new hardware correlator
in Korea, the Daejeon correlator, developed by the Korea Astronomy and Space
Science Institute (KASI) and the National Astronomical Observatory of Japan
(NAOJ). We conducted Very Long Baseline Interferometry (VLBI) observations at
22~GHz with the Korean VLBI Network (KVN) in Korea and the VLBI Exploration of
Radio Astrometry (VERA) in Japan, and correlated the aquired data with the
Daejeon correlator. For evaluating the performance of the new hardware
correlator, we compared the correlation outputs from the Daejeon correlator for
KVN observations with those from a software correlator, the Distributed FX
(DiFX). We investigated the correlated flux densities and brightness
distributions of extragalactic compact radio sources. The comparison of the two
correlator outputs show that they are consistent with each other within ,
which is comparable with the amplitude calibration uncertainties of KVN
observations at 22~GHz. We also found that the 8\% difference in flux density
is caused mainly by (a) the difference in the way of fringe phase tracking
between the DiFX software correlator and the Daejeon hardware correlator, and
(b) an unusual pattern (a double-layer pattern) of the amplitude correlation
output from the Daejeon correlator. The visibility amplitude loss by the
double-layer pattern is as small as 3\%. We conclude that the new hardware
correlator produces reasonable correlation outputs for continuum observations,
which are consistent with the outputs from the DiFX software correlator.Comment: 13 pagee, 9 figures, 3 tables, to appear in JKAS (received February
9, 2015; accepted March 16, 2015
Green Synthesis of Gold Nanoparticles Using Aqueous Extract of Garcinia mangostana
The synthesis of gold nanoparticles (Au-NPs) is performed by the reduction of aqueous gold metal ions in contact with the aqueous peel extract of plant, Garcinia mangostana (G. mangostana). An absorption peak of the gold nanoparticles is observed at the range of 540–550 nm using UV-visible spectroscopy. All the diffraction peaks at 2θ = 38.48°, 44.85°, 66.05°, and 78.00° that index to (111), (200), (220), and (311) planes confirm the successful synthesis of Au-NPs. Mostly spherical shape particles with size range of 32.96 ± 5.25 nm are measured using transmission electron microscopy (TEM). From the FTIR results, the peaks obtained are closely related to phenols, flavonoids, benzophenones, and anthocyanins which suggest that they may act as the reducing agent. This method is environmentally safe without the usage of synthetic materials which is highly potential in biomedical applications
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