4,068 research outputs found
Improved storage of coherent and squeezed states in imperfect ring cavity
We propose a method of an improving quality of a ring cavity which is
imperfect due to non-unit mirror reflectivity. The method is based on using
squeezed states of light pulses illuminating the mirror and gradual homodyne
detection of a radiation escaping from the cavity followed by single
displacement and single squeezing operation performed on the released state. We
discuss contribution of this method in process of storing unknown coherent and
known squeezed state and generation of squeezing in the optical ring cavities.Comment: 6 pages and 5 figure
Elementary gates for quantum information with superposed coherent states
We propose a new way of implementing several elementary quantum gates for
qubits in the coherent state basis. The operations are probabilistic and employ
single photon subtractions as the driving force. Our schemes for single-qubit
phase gate and two-qubit controlled phase gate are capable of achieving
arbitrarily large phase shifts with currently available resources, which makes
them suitable for the near-future tests of quantum information processing with
superposed coherent states.Comment: 4 pages, 4 figures, accepted versio
Noise resilient quantum interface based on QND interaction
We propose a quantum interface protocol based on two quantum-non-demolition
interactions (QND) arranged either in sequence or in parallel. Since the QND
coupling arises naturally in interactions between light and a macroscopic
ensemble of atoms, or between light and a micro-mechanical oscillator, the
proposed interface is capable of transferring a state of light onto these
matter systems. The transfer itself is perfect and deterministic for any
quantum state, for arbitrarily small interaction strengths, and for arbitrarily
large noise of the target system. It requires an all-optical pre-processing,
requiring a coupling stronger than that between the light and the matter, and a
displacement feed-forward correction of the matter system. We also suggest a
probabilistic version of the interface, which eliminates the need for the
feed-forward correction at a cost of reduced success rate. An application of
the interface can be found in construction of a quantum memory, or in the state
preparation for quantum sensing.Comment: 6 pages, 5 figure
Coherent-state phase concentration by quantum probabilistic amplification
We propose novel coherent-state phase concentration by probabilistic
measurement-induced ampli- fication. The amplification scheme uses novel
architecture, thermal noise addition (instead of single photon addition)
followed by feasible multiple photon subtraction using realistic photon-number
resolving detector. It allows to substantially amplify weak coherent states and
simultaneously reduce their phase uncertainty, contrary to the deterministic
amplifier
Design and development of a novel Invasive Blood Pressure simulator for patient's monitor testing
This paper presents a newly-designed and realized Invasive Blood Pressure (IBP) device for the simulation on patient’s monitors. This device shows improvements and presents extended features with respect to a first prototype presented by the authors and similar systems available in the state-of-the-art. A peculiarity of the presented device is that all implemented features can be customized from the developer and from the point of view of the end user. The realized device has been tested, and its performances in terms of accuracy and of the back-loop measurement of the output for the blood pressure regulation utilization have been described. In particular, an accuracy of ±1 mmHg at 25 °C, on a range from −30 to 300 mmHg, was evaluated under different test conditions. The designed device is an ideal tool for testing IBP modules, for zero setting, and for calibrations. The implemented extended features, like the generation of custom waveforms and the Universal Serial Bus (USB) connectivity, allow use of this device in a wide range of applications, from research to equipment maintenance in clinical environments to educational purposes. Moreover, the presented device represents an innovation, both in terms of technology and methodologies: It allows quick and efficient tests to verify the proper functioning of IBP module of patients’ monitors. With this innovative device, tests can be performed directly in the field and faster procedures can be implemented by the clinical maintenance personnel. This device is an open source project and all materials, hardware, and software are fully available for interested developers or researchers.Web of Science201art. no. 25
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