scholarly journals Preserving Nonclassicality in Noisy Communication Channels

Proceedings ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 3 ◽  
Author(s):  
Alessia Allevi ◽  
Maria Bondani
Keyword(s):  
Quantum Information ◽  
Photon Number ◽  
Communication Channels ◽  
Global Scale ◽  
Noisy Channels ◽  
Space Communication ◽  
Main Obstacle ◽  
Cryptographic Keys ◽  
Light Signals ◽  
Twin Beam

Nowadays, the transmission of quantum information, especially for the distribution of cryptographic keys, is required on a global scale. The main obstacle to overcome in free-space communication is the presence of turbulence, which causes both spatial and temporal deformations of the light signals that code information. Here we investigate the extent at which the transmission of mesoscopic twin-beam states through asymmetric noisy channels degrades the nonclassical nature of the photon-number correlations between signal and idler. We consider three nonclassicality criteria, all written in terms of measurable quantities, and demonstrate, both theoretically and experimentally, that the asymmetry introduced by losses affects the three criteria in different ways.

scholarly journals Measuring Nonclassicality of Mesoscopic Twin-Beam States with Silicon Photomultipliers †

Proceedings ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 48
Author(s):  
Giovanni Chesi ◽  
Luca Malinverno ◽  
Alessia Allevi ◽  
Romualdo Santoro ◽  
Massimo Caccia ◽  
...  
Keyword(s):  
Quantum Information ◽  
Quantum Optics ◽  
Output Signal ◽  
Photon Number ◽  
Quantum States ◽  
Silicon Photomultipliers ◽  
Nonclassical Properties ◽  
Relevant Topic ◽  
Twin Beam ◽  
Proper Analysis

The study of nonclassical properties of quantum states is a relevant topic for fundamental Quantum Optics and Quantum Information applications. In the mesoscopic domain, promising results have been obtained using photon-number-resolving detectors. Here we show recent results achieved with the class of Silicon Photomultipliers: by a proper analysis of the output signal, the nonclassicality of twin-beam states can be detected and exploited.

scholarly journals Exploiting Silicon photomultipliers for measuring nonclassical optical states

2020 ◽  
Vol 230 ◽  
pp. 00002
Author(s):  
Giovanni Chesi ◽  
Alessia Allevi ◽  
Maria Bondani
Keyword(s):  
Quantum Information ◽  
Quantum Optics ◽  
Communication Protocols ◽  
Photon Number ◽  
Optimization Procedure ◽  
Silicon Photomultipliers ◽  
Information And Communication ◽  
Twin Beam

The search for optimal receivers endowed with photon-number-resolving capability has led us to consider Silicon photomultipliers for Quantum Optics experiments. By adopting an optimization procedure in order to reduce the spurious effects characterizing these detectors, we succeeded in detecting nonclassical correlations between the two parties of mesoscopic twin-beam states and in obtaining subPoissonian conditional states. These results put SiPMs forward for the implementation of Quantum Information and Communication protocols.

scholarly journals Procedure via cross-Kerr nonlinearities for encoding single logical qubit information onto four-photon decoherence-free states

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jino Heo ◽  
Seong-Gon Choi
Keyword(s):  
Quantum Information ◽  
Quantum Information Processing ◽  
Photon Number ◽  
Optical Devices ◽  
Quantum Bus ◽  
Reliable Procedure ◽  
Optical Gates ◽  
Photon Loss ◽  
Decoherence Effect ◽  
Logical Qubit

AbstractWe propose a photonic procedure using cross-Kerr nonlinearities (XKNLs) to encode single logical qubit information onto four-photon decoherence-free states. In quantum information processing, a decoherence-free subspace can secure quantum information against collective decoherence. Therefore, we design a procedure employing nonlinear optical gates, which are composed of XKNLs, quantum bus beams, and photon-number-resolving measurements with linear optical devices, to conserve quantum information by encoding quantum information onto four-photon decoherence-free states (single logical qubit information). Based on our analysis in quantifying the affection (photon loss and dephasing) of the decoherence effect, we demonstrate the experimental condition to acquire the reliable procedure of single logical qubit information having the robustness against the decoherence effect.

Homodyne-like detection scheme based on photon-number-resolving detectors

2017 ◽  
Vol 15 (08) ◽  
pp. 1740016 ◽  
Author(s):  
Alessia Allevi ◽  
Matteo Bina ◽  
Stefano Olivares ◽  
Maria Bondani
Keyword(s):  
Coherent States ◽  
Beam Splitter ◽  
Photon Number ◽  
Local Oscillator ◽  
Quantum States ◽  
Homodyne Detection ◽  
Detection Scheme ◽  
Light Signals ◽  
The Difference ◽  
Signal Field

Homodyne detection is the most effective detection scheme employed in quantum optics to characterize quantum states. It is based on mixing at a beam splitter the signal to be measured with a coherent state, called the “local oscillator,” and on evaluating the difference of the photocurrents of two photodiodes measuring the outputs of the beam splitter. If the local oscillator is much more intense than the field to be measured, the homodyne signal is proportional to the signal-field quadratures. If the local oscillator is less intense, the photodiodes can be replaced with photon-number-resolving detectors, which have a smaller dynamics but can measure the light statistics. The resulting new homodyne-like detector acquires a hybrid nature, being it capable of yielding information on both the particle-like (statistics) and wave-like (phase) properties of light signals. The scheme has been tested in the measurement of the quadratures of coherent states, bracket states and phase-averaged coherent states at different intensities of the local oscillator.

Probabilistic secret sharing through noise quantum channe

2012 ◽  
Vol 12 (3&4) ◽  
pp. 253-261
Author(s):  
Satyabrata Adhikari ◽  
Indranil Chakrabarty ◽  
Pankaj Agrawal
Keyword(s):  
Quantum Information ◽  
Secret Sharing ◽  
Mixed State ◽  
Pure State ◽  
Noisy Channel ◽  
Noisy Channels ◽  
Superdense Coding ◽  
Classical Information ◽  
Phase Damping ◽  
Realistic Situation

In a realistic situation, the secret sharing of classical or quantum information will involve the transmission of this information through noisy channels. We consider a three qubit pure state. This state becomes a mixed-state when the qubits are distributed over noisy channels. We focus on a specific noisy channel, the phase-damping channel. We propose a protocol for secret sharing of classical information with this and related noisy channels. This protocol can also be thought of as cooperative superdense coding. We also discuss other noisy channels to examine the possibility of secret sharing of classical information.

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