1,263 research outputs found
Simple scheme for expanding a polarization-entangled W state by adding one photon
We propose a simple scheme for expanding a polarization-entangled W state. By
mixing a single photon and one of the photons in an n-photon W state at a
polarization-dependent beam splitter (PDBS), we can obtain an (n+1)-photon W
state after post-selection. Our scheme also opens the door for generating
n-photon W states using single photons and linear optics.Comment: 3 pages, 2 figure
Production and optical properties of liquid scintillator for the JSNS experiment
The JSNS (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron
Source) experiment will search for neutrino oscillations over a 24 m short
baseline at J-PARC. The JSNS inner detector will be filled with 17 tons
of gadolinium-loaded liquid scintillator (LS) with an additional 31 tons of
unloaded LS in the intermediate -catcher and outer veto volumes.
JSNS has chosen Linear Alkyl Benzene (LAB) as an organic solvent because
of its chemical properties. The unloaded LS was produced at a refurbished
facility, originally used for scintillator production by the RENO experiment.
JSNS plans to use ISO tanks for the storage and transportation of the LS.
In this paper, we describe the LS production, and present measurements of its
optical properties and long term stability. Our measurements show that storing
the LS in ISO tanks does not result in degradation of its optical properties.Comment: 7 pages, 4 figures
Quantum teleportation via a W state
We investigate two schemes of the quantum teleportation with a state,
which belongs to a different class from a Greenberger-Horne-Zeilinger class. In
the first scheme, the state is shared by three parties one of whom, called
a sender, performs a Bell measurement. It is shown that quantum information of
an unknown state is split between two parties and recovered with a certain
probability. In the second scheme, a sender takes two particles of the
state and performs positive operator valued measurements in two ways. For two
schemes, we calculate the success probability and the average fidelity. We show
that the average fidelity of the second scheme cannot exceed that of the first
one.Comment: 7 pages, 1 figur
Generation of Three-Qubit Entangled W-State by Nonlinear Optical State Truncation
We propose an alternative scheme to generate W state via optical state
truncation using quantum scissors. In particular, these states may be generated
through three-mode optical state truncation in a Kerr nonlinear coupler. The
more general three-qubit state may be also produced if the system is driven by
external classical fields.Comment: 7 pages, 2 figur
The states of W-class as shared resources for perfect teleportation and superdense coding
As we know, the states of triqubit systems have two important classes:
GHZ-class and W-class.
In this paper, the states of W-class are considered for teleportation and
superdense coding, and are generalized to multi-particle systems. First we
describe two transformations of the shared resources for teleportation and
superdense coding, which allow many new protocols from some known ones for
that. As an application of these transformations, we obtain a sufficient and
necessary condition for a state of W-class being suitable for perfect
teleportation and superdense coding. As another application, we find that state
can be used to
transmit three classical bits by sending two qubits, which was considered to be
impossible by P. Agrawal and A. Pati [Phys. Rev. A to be published]. We
generalize the states of W-class to multi-qubit systems and multi-particle
systems with higher dimension. We propose two protocols for teleportation and
superdense coding by using W-states of multi-qubit systems that generalize the
protocols by using proposed by P. Agrawal and A. Pati. We obtain an
optimal way to partition some W-states of multi-qubit systems into two
subsystems, such that the entanglement between them achieves maximum value.Comment: 10 pages, critical comments and suggestions are welcom
Local expansion of photonic W state using a polarization dependent beamsplitter
We propose a simple probabilistic optical gate to expand polarization
entangled W states. The gate uses one polarization-dependent beamsplitter and a
horizontally polarized single photon as an ancilla. The gate post-selectively
expands -photon W states to -photon W states. A feasibility analysis
considering the realistic experimental conditions show that the scheme is
within the reach of the current quantum optical technologies.Comment: 10 pages, 5 figure
Slow Control Systems of the Reactor Experiment for Neutrino Oscillation
The RENO experiment has been in operation since August 2011 to measure
reactor antineutrino disappearance using identical near and far detectors. For
accurate measurements of neutrino mixing parameters and efficient data taking,
it is crucial to monitor and control the detector in real time. Environmental
conditions also need to be monitored for stable operation of detectors as well
as for safety reasons. In this article, we report the design, hardware,
operation, and performance of the slow control system
Measurement of cosmogenic Li and He production rates at RENO
We report the measured production rates of unstable isotopes Li and
He produced by cosmic muon spallation on C using two identical
detectors of the RENO experiment. Their beta-decays accompanied by a neutron
make a significant contribution to backgrounds of reactor antineutrino events
in precise determination of the smallest neutrino mixing angle. The mean muon
energy of its near (far) detector with an overburden of 120 (450) m.w.e. is
estimated as 33.1 +- 2.3 (73.6 +- 4.4) GeV. Based on roughly 3100 days of data,
the cosmogenic production rate of Li (He) isotope is measured to be
44.2 +- 3.1 (10.6 +- 7.4) per day at near detector and 10.0 +- 1.1 (2.1 +- 1.5)
per day at far detector. This corresponds to yields of Li (He), 4.80 +-
0.36 (1.15 +- 0.81) and 9.9 +- 1.1 (2.1 +- 1.5) at near and far detectors,
respectively, in a unit of 10 g cm. Combining
the measured Li yields with other available underground measurements, an
excellent power-law relationship of the yield with respect to the mean muon
energy is found to have an exponent of = 0.76 +- 0.05.Comment: 11 pages, 14 figure
Time and Amplitude of Afterpulse Measured with a Large Size Photomultiplier Tube
We have studied the afterpulse of a hemispherical photomultiplier tube for an
upcoming reactor neutrino experiment. The timing, the amplitude, and the rate
of the afterpulse for a 10 inch photomultiplier tube were measured with a 400
MHz FADC up to 16 \ms time window after the initial signal generated by an LED
light pulse. The time and amplitude correlation of the afterpulse shows several
distinctive groups. We describe the dependencies of the afterpulse on the
applied high voltage and the amplitude of the main light pulse. The present
data could shed light upon the general mechanism of the afterpulse.Comment: 11 figure
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