scholarly journals Wigner representation for polarization-momentum hyperentanglement generated in parametric down-conversion, and its application to complete Bell-state measurement

2014 ◽  
Vol 68 (11) ◽  
Author(s):  
Alberto Casado ◽  
Santiago Guerra ◽  
José Plácido
Keyword(s):  
Bell State ◽  
Bell State Measurement ◽  
State Measurement ◽  
Parametric Down Conversion ◽  
Wigner Representation ◽  
Down Conversion

scholarly journals Partial Bell-State Analysis with Parametric down Conversion in the Wigner Function Formalism

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
A. Casado ◽  
S. Guerra ◽  
J. Plácido
Keyword(s):  
Wigner Function ◽  
Beam Splitter ◽  
Bell State ◽  
Function Formalism ◽  
State Measurement ◽  
Parametric Down Conversion ◽  
Correlation Properties ◽  
Light Beams ◽  
Down Conversion ◽  
State Analysis

We apply the Wigner function formalism to partial Bell-state analysis using polarization entanglement produced in parametric down conversion. Two-photon statistics at a beam-splitter are reproduced by a wave-like description with zeropoint fluctuations of the electromagnetic field. In particular, the fermionic behaviour of two photons in the singlet state is explained from the invariance on the correlation properties of two light beams going through a balanced beam-splitter. Moreover, we show that a Bell-state measurement introduces some fundamental noise at the idle channels of the analyzers. As a consequence, the consideration of more independent sets of vacuum modes entering the crystal appears as a need for a complete Bell-state analysis.

scholarly journals Practical quantum teleportation of an unknown quantum state

2017 ◽  
Vol 95 (5) ◽  
pp. 498-503
Author(s):  
Syed Tahir Amin ◽  
Aeysha Khalique
Keyword(s):  
Quantum State ◽  
Quantum Teleportation ◽  
Bell State ◽  
Linear Optics ◽  
State Measurement ◽  
Dark Counts ◽  
Experimental Parameters ◽  
Unknown Quantum State ◽  
Down Conversion ◽  
Good Agreement

We present our model to teleport an unknown quantum state using entanglement between two distant parties. Our model takes into account experimental limitations due to contribution of multi-photon pair production of parametric down conversion source, inefficiency, dark counts of detectors, and channel losses. We use a linear optics setup for quantum teleportation of an unknown quantum state by the sender performing a Bell state measurement. Our theory successfully provides a model for experimentalists to optimize the fidelity by adjusting the experimental parameters. We apply our model to a recent experiment on quantum teleportation and the results obtained by our model are in good agreement with the experimental results.

QUANTUM AUTHENTICATION USING ENTANGLED STATES

2004 ◽  
Vol 15 (04) ◽  
pp. 609-617 ◽  
Author(s):  
XIAOYU LI ◽  
HOWARD BARNUM
Keyword(s):  
Bell State ◽  
Authentication Scheme ◽  
Entangled States ◽  
Bell State Measurement ◽  
Epr Pairs ◽  
State Measurement ◽  
Quantum Authentication ◽  
Einstein Podolsky Rosen

A quantum authentication scheme is presented in this paper. Two parties share Einstein-Podolsky-Rosen(EPR) pairs previously as the identification token. They create auxiliary EPR pairs to interact with the identification token. Then the authentication is accomplished by a complete Bell state measurement. This scheme is proved to be secure. If no errors and eavesdroppers exist in the transmission, the identification token is unchanged after the authentication. So it can be reused.

Single-photon Bell state measurement based on a quantum random walk

2019 ◽  
Vol 100 (4) ◽  
Author(s):  
Xiao-Xiao Chen ◽  
Jia-Zhi Yang ◽  
Xu-Dan Chai ◽  
An-Ning Zhang
Keyword(s):  
Random Walk ◽  
Single Photon ◽  
Bell State ◽  
Quantum Random Walk ◽  
Bell State Measurement ◽  
State Measurement

scholarly journals Local Realistic Theory for PDC Experiments Based on the Wigner Formalism

2001 ◽  
Vol 56 (1-2) ◽  
pp. 178-181 ◽  
Author(s):  
Alberto Casado ◽  
Ramón Risco-Delgado ◽  
Emilio Santos
Keyword(s):  
Quantum Theory ◽  
Radiation Field ◽  
Hidden Variables ◽  
Standard Quantum ◽  
Realistic Theory ◽  
Photon Pairs ◽  
Parametric Down Conversion ◽  
Wigner Representation ◽  
Down Conversion ◽  
Made In

Abstract In this article we present a local hidden variables model for all experiments involving photon pairs produced in parametric down conversion, based on the Wigner representation of the radiation field. A modification of the standard quantum theory of detection is made in order to give a local realistic explanation of the counting rates in photodetectors. This model involves the existence of a real zeropoint field, such that the vacumm level of radiation lies below the threshold of the detectors.

scholarly journals From Stochastic Optics to theWigner Formalism: The Role of the Vacuum Field in Optical Quantum Communication Experiments

Atoms ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 76 ◽  
Author(s):  
Alberto Casado ◽  
Santiago Guerra ◽  
José Plácido
Keyword(s):  
Quantum Cryptography ◽  
Physical Meaning ◽  
Quantum Communication ◽  
Bell State ◽  
Vacuum Field ◽  
Heisenberg Picture ◽  
Parametric Down Conversion ◽  
The Relationship ◽  
Down Conversion

TheWigner formalism in the Heisenberg picture constitutes a bridge that connects QuantumOptics to Stochastic Optics. The vacuum field appears explicitly in the formalism, and the wavelikeaspects of light are emphasised. In addition, the zeropoint intensity as a threshold for detection is acommon denominator in both theories. In this paper, after summarising the basic rules of the Wignerapproach and its application to parametric down-conversion, some new results are presented thatdelve into the physical meaning of the zeropoint field in optical quantum communication. Specifically,the relationship between Bell-state distinguishability and the number of sets of zeropoint modesthat take part in the experiment is analysed in terms of the coupling between the phases of thedifferent fields involved and the subtraction of the zeropoint intensity at the detectors. Additionally,the connection between the compatibility theorem in quantum cryptography and zeropoint fieldis stressed.

Sign in / Sign up

Export Citation Format

Share Document