206 research outputs found
Quantum teleportation from a telecom-wavelength photon to a solid-state quantum memory
In quantum teleportation, the state of a single quantum system is disembodied
into classical information and purely quantum correlations, to be later
reconstructed onto a second system that has never directly interacted with the
first one. This counterintuitive phenomenon is a cornerstone of quantum
information science due to its essential role in several important tasks such
as the long-distance transmission of quantum information using quantum
repeaters. In this context, a challenge of paramount importance is the
distribution of entanglement between remote nodes, and to use this entanglement
as a resource for long-distance light-to-matter quantum teleportation. Here we
demonstrate quantum teleportation of the polarization state of a
telecom-wavelength photon onto the state of a solid-state quantum memory.
Entanglement is established between a rare-earth-ion doped crystal storing a
single photon that is polarization-entangled with a flying telecom-wavelength
photon. The latter is jointly measured with another flying qubit carrying the
polarization state to be teleported, which heralds the teleportation. The
fidelity of the polarization state of the photon retrieved from the memory is
shown to be greater than the maximum fidelity achievable without entanglement,
even when the combined distances travelled by the two flying qubits is 25 km of
standard optical fibre. This light-to-matter teleportation channel paves the
way towards long-distance implementations of quantum networks with solid-state
quantum memories.Comment: 5 pages (main text) + appendix (10 pages
Modern Going Near Application of Respiratory Exercises at Obesity for Women
У статті розглядається методика дихальної гімнастики «Бодіфлекс»під час реабілітації жінок з ожирінням.In the article the method of respiratory gymnastics of «Bodifleks»pid is examined time of rehabilitation of women with obesity
High-efficiency WSi superconducting nanowire single-photon detectors operating at 2.5 K
We investigate the operation of WSi superconducting nanowire single-photon
detectors (SNSPDs) at 2.5 K, a temperature which is ~ 70 % of the
superconducting transition temperature (TC) of 3.4 K. We demonstrate saturation
of the system detection efficiency at 78 +- 2 % with a jitter of 191 ps. We
find that the jitter at 2.5 K is limited by the noise of the readout, and can
be improved through the use of cryogenic amplifiers. Operation of SNSPDs with
high efficiency at temperatures very close to TC appears to be a unique
property of amorphous WSi
High-efficiency superconducting nanowire single-photon detectors fabricated from MoSi thin-films
We demonstrate high-efficiency superconducting nanowire single-photon
detectors (SNSPDs) fabricated from MoSi thin-films. We measure a maximum system
detection efficiency (SDE) of 87 +- 0.5 % at 1542 nm at a temperature of 0.7 K,
with a jitter of 76 ps, maximum count rate approaching 10 MHz, and polarization
dependence as low as 3.4 +- 0.7 % The SDE curves show saturation of the
internal efficiency similar to WSi-based SNSPDs at temperatures as high as 2.3
K. We show that at similar cryogenic temperatures, MoSi SNSPDs achieve
efficiencies comparable to WSi-based SNSPDs with nearly a factor of two
reduction in jitter
Frequency-domain multiplexing of SNSPDs with tunable superconducting resonators
This work culminates in a demonstration of an alternative Frequency Domain
Multiplexing (FDM) scheme for Superconducting Nanowire Single-Photon Detectors
(SNSPDs) using the Kinetic inductance Parametric UP-converter (KPUP) made out
of NbTiN. There are multiple multiplexing architectures for SNSPDs that are
already in use, but FDM could prove superior in applications where the
operational bias currents are very low, especially for mid- and far-infrared
SNSPDs. Previous FDM schemes integrated the SNSPD within the resonator, while
in this work we use an external resonator, which gives more flexibility to
optimize the SNSPD architecture. The KPUP is a DC-biased superconducting
resonator in which a nanowire is used as its inductive element to enable
sensitivity to current perturbations. When coupled to an SNSPD, the KPUP can be
used to read out current pulses on the few A scale. The KPUP is made out
of NbTiN, which has high non-linear kinetic inductance for increased
sensitivity at higher current bias and high operating temperature. Meanwhile,
the SNSPD is made from WSi, which is a popular material for broadband SNSPDs.
To read out the KPUP and SNSPD array, a software-defined radio platform and a
graphics processing unit are used. Frequency Domain Multiplexed SNSPDs have
applications in astronomy, remote sensing, exoplanet science, dark matter
detection, and quantum sensing
Wnt Signaling Is Required for Early Development of Zebrafish Swimbladder
10.1371/journal.pone.0018431PLoS ONE63
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