26 research outputs found
Remote preparation of continuous-variable qubits using loss-tolerant hybrid entanglement of light
Transferring quantum information between distant nodes of a network is a key
capability. This transfer can be realized via remote state preparation where
two parties share entanglement and the sender has full knowledge of the state
to be communicated. Here we demonstrate such a process between heterogeneous
nodes functioning with different information encodings, i.e., particle-like
discrete-variable optical qubits and wave-like continuous-variable ones. Using
hybrid entanglement of light as a shared resource, we prepare arbitrary
coherent-state superpositions controlled by measurements on the distant
discrete-encoded node. The remotely prepared states are fully characterized by
quantum state tomography and negative Wigner functions are obtained. This work
demonstrates a novel capability to bridge discrete- and continuous-variable
platforms
High-efficiency WSi superconducting nanowire single-photon detectors for quantum state engineering in the near infrared
We report on high-efficiency superconducting nanowire single-photon detectors
based on amorphous WSi and optimized at 1064 nm. At an operating temperature of
1.8 K, we demonstrated a 93% system detection efficiency at this wavelength
with a dark noise of a few counts per second. Combined with cavity-enhanced
spontaneous parametric down-conversion, this fiber-coupled detector enabled us
to generate narrowband single photons with a heralding efficiency greater than
90% and a high spectral brightness of
photons/(smWMHz). Beyond single-photon generation at large rate,
such high-efficiency detectors open the path to efficient multiple-photon
heralding and complex quantum state engineering
Demonstration of Einstein-Podolsky-Rosen Steering Using Hybrid Continuous- and Discrete-Variable Entanglement of Light
Einstein-Podolsky-Rosen steering is known to be a key resource for one-sided
device-independent quantum information protocols. Here we demonstrate steering
using hybrid entanglement between continuous- and discrete-variable optical
qubits. To this end, we report on suitable steering inequalities and detail the
implementation and requirements for this demonstration. Steering is
experimentally certified by observing a violation by more than 5 standard
deviations. Our results illustrate the potential of optical hybrid entanglement
for applications in heterogeneous quantum networks that would interconnect
disparate physical platforms and encodings
The Treatment In Morning versus Evening (TIME) study:Analysis of recruitment, follow-up and retention rates post-recruitment
Abstract Background The use of information technology (IT) is now the preferred method of capturing and storing clinical research data. The Treatment In Morning versus Evening (TIME) study predominantly uses electronic data capture and IT to compare morning dosing of hypertensive medication against evening dosing. Registration, consent, participant demographics and follow-up data are all captured via the study website. The aim of this article is to assess the success of the TIME methodology compared with similar studies. Methods To assess the TIME study, published literature on similar clinical trials was reviewed and compared against TIME recruitment, follow-up and email interaction data. Results The TIME website registered 31,695 individuals, 21,116 of whom were randomised. Recruitment cost per randomised participant varied by strategy: £17.40 by GP practice, £3.08 by UK Biobank and £58.82 for GoShare. Twelve-month follow-up retention rates were 96%. A total of 1089 participants have withdrawn from their assigned time of dosing, 2% of whom have declined follow-up by record linkage or further contact. When the TIME data are compared with similar study data, study recruitment is very successful. However, TIME suffers difficulties with participant follow-up and withdrawal rates similar to those of conventional studies. Conclusions The TIME study has been successful in recruitment. Follow-up, retention rates and withdrawal rates are all acceptable, but ongoing work is required to ensure participants remain engaged with the study. Various recruitment strategies are necessary, and all viable options should be encouraged to maintain participant engagement throughout the life of studies using IT