74 research outputs found
Mapping photonic entanglement into and out of a quantum memory
Recent developments of quantum information science critically rely on
entanglement, an intriguing aspect of quantum mechanics where parts of a
composite system can exhibit correlations stronger than any classical
counterpart. In particular, scalable quantum networks require capabilities to
create, store, and distribute entanglement among distant matter nodes via
photonic channels. Atomic ensembles can play the role of such nodes. So far, in
the photon counting regime, heralded entanglement between atomic ensembles has
been successfully demonstrated via probabilistic protocols. However, an
inherent drawback of this approach is the compromise between the amount of
entanglement and its preparation probability, leading intrinsically to low
count rate for high entanglement. Here we report a protocol where entanglement
between two atomic ensembles is created by coherent mapping of an entangled
state of light. By splitting a single-photon and subsequent state transfer, we
separate the generation of entanglement and its storage. After a programmable
delay, the stored entanglement is mapped back into photonic modes with overall
efficiency of 17 %. Improvements of single-photon sources together with our
protocol will enable "on demand" entanglement of atomic ensembles, a powerful
resource for quantum networking.Comment: 7 pages, and 3 figure
Conditional control of the quantum states of remote atomic memories for quantum networking
Quantum networks hold the promise for revolutionary advances in information
processing with quantum resources distributed over remote locations via
quantum-repeater architectures. Quantum networks are composed of nodes for
storing and processing quantum states, and of channels for transmitting states
between them. The scalability of such networks relies critically on the ability
to perform conditional operations on states stored in separated quantum
memories. Here we report the first implementation of such conditional control
of two atomic memories, located in distinct apparatuses, which results in a
28-fold increase of the probability of simultaneously obtaining a pair of
single photons, relative to the case without conditional control. As a first
application, we demonstrate a high degree of indistinguishability for remotely
generated single photons by the observation of destructive interference of
their wavepackets. Our results demonstrate experimentally a basic principle for
enabling scalable quantum networks, with applications as well to linear optics
quantum computation.Comment: 10 pages, 8 figures; Minor corrections. References updated. Published
at Nature Physics 2, Advanced Online Publication of 10/29 (2006
Potential use of fatty acid profiles of the adductor muscle of cockles (Cerastoderma edule) for traceability of collection site
Geographic traceability of seafood is key for controlling its quality and safeguarding consumers’
interest. The present study assessed if the fatty acid (FA) profile of the adductor muscle (AM) of
fresh cockles (Cerastoderma edule) can be used to discriminate the origin of specimens collected in
different bivalve capture/production areas legally defined within a coastal lagoon. Results suggest
that this biochemical approach holds the potential to trace sampling locations with a spatial
resolution <10 Km, even for areas with identical classification for bivalve production. Cockles further
away from the inlet, i.e. in areas exposed to a higher saline variation, exhibited lower levels of
saturated fatty acids, which are key for stabilizing the bilayer structure of cell membranes, and a
higher percentage of polyunsaturated fatty acids, which enhance bilayer fluidity. Results suggest that
the structural nature of the lipids present in the AM provides a stable fatty acid signature and holds
potential for tracing the origin of bivalves to their capture/production areas
A sensory and nutritional validation of open ocean mussels (Mytilus galloprovincialis Lmk.) cultured in SE Bay of Biscay (Basque Country) compared to their commercial counterparts from Galician Rías (Spain)
Glycymeris bimaculata (Poli, 1795) — A new sclerochronological archive for the Mediterranean?
Remapping of depth of e-log markers between Neogene basement and Lower/Upper Pannonian border in the Bjelovar Subdepression
High-pressure X-ray study of LiCrSi2O6 clinopyroxene and the general compressibility trends for Li-clinopyroxenes
Sequential Indicator Simulations maps of porosity, depth and thickness of Miocene clastic sediments in the Kloštar field, Northern Croatia
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