4,442 research outputs found
Storage and Retrieval of Thermal Light in Warm Atomic Vapor
We report slowed propagation and storage and retrieval of thermal light in
warm rubidium vapor using the effect of electromagnetically-induced
transparency (EIT). We first demonstrate slowed-propagation of the probe
thermal light beam through an EIT medium by measuring the second-order
correlation function of the light field using the Hanbury-BrownTwiss
interferometer. We also report an experimental study on the effect of the EIT
slow-light medium on the temporal coherence of thermal light. Finally, we
demonstrate the storage and retrieval of thermal light beam in the EIT medium.
The direct measurement of the photon number statistics of the retrieved light
field shows that the photon number statistics is preserved during the storage
and retrieval process.Comment: 4 pages, 4 figure
Explaining the Color Distributions of Globular Cluster Systems in Elliptical Galaxies
The colors of globular clusters in most of large elliptical galaxies are
bimodal. This is generally taken as evidence for the presence of two cluster
subpopulations that have different geneses. However, here we find that, because
of the non-linear nature of the metallicity-to-color transformation, a coeval
group of old clusters with a unimodal metallicity spread can exhibit color
bimodality. The models of cluster colors indicate that the horizontal-branch
stars are the main drivers behind the empirical non-linearity. We show that the
scenario gives simple and cohesive explanations for all the key observations,
and could simplify theories of elliptical galaxy formation.Comment: Science, 311, 1129; Minor changes to text to match the published
version (9 pages, 3 figures
Evaluation of an Emergency Radiology Quality Assurance Program at a Level One Trauma Center and Clinical Consequences of Radiologic Errors \u27
Reversing the Weak Quantum Measurement for a Photonic Qubit
We demonstrate the conditional reversal of a weak (partial-collapse) quantum
measurement on a photonic qubit. The weak quantum measurement causes a
nonunitary transformation of a qubit which is subsequently reversed to the
original state after a successful reversing operation. Both the weak
measurement and the reversal operation are implemented linear optically. The
state recovery fidelity, determined by quantum process tomography, is shown to
be over 94% for partial-collapse strength up to 0.9. We also experimentally
study information gain due to the weak measurement and discuss the role of the
reversing operation as an information erasure
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