Dependence of Entangled States and Franson - type EPR Experiments
نویسندگان
چکیده
We analyze some aspects of recently performed Franson-type experiments with entangled photon pairs aimed to test Bell's inequalities. We point out that quantum theory leads to the coincidence rate between detectors which includes in fact a dependence on the distance. We study this dependence and obtain that for large distances the correlation function vanishes. Therefore with taking into account the space parts of wave functions of photons for large distances quantum mechanical predictions are consistent with Bell's inequalities. We propose an experimental study of space dependence of correlation functions in Bell-type experiments.
منابع مشابه
Quantum Cryptography with Femtosecond Parametric down Conversion
We experimentally demonstrate a quantum cryptography system using two-photon entangled (EPR) states generated via the nonlinear process of spontaneous parametric down conversion pumped by a femtosecond laser. There are two major approaches in quantum cryptography which historically appeared almost simultaneously. One uses the quantum features of single photon states produced by signi cant atten...
متن کاملQuantum metrology with entangled photons
Although most physics experiments are carried out with independent particles, it is the collective nature of entangled particles that reveals the most fascinating and unexpected aspects of the quantum world. It was Erwin Schrödinger who first said “entanglement is not one but rather the characteristic trait of quantum mechanics”. One curious aspect of the behavior of a pair of particles in an e...
متن کاملEnergy-time entanglement, elements of reality, and local realism
The Franson interferometer, proposed in 1989 [J. D. Franson, Phys. Rev. Lett. 62:2205–2208 (1989)], beautifully shows the counter-intuitive nature of light. The quantum description predicts sinusoidal interference for specific outcomes of the experiment, and these predictions can be verified in experiment. In the spirit of Einstein, Podolsky, and Rosen it is possible to ask if the quantum-mecha...
متن کاملRegularised Tripartite Continuous Variable EPR-type States with Wigner Functions and CHSH Violations
We consider tripartite entangled states for continuous variable systems of EPR type, which generalise the famous bipartite CV EPR states (eigenvectors of conjugate choices X1−X2, P1+ P2, of the systems’ relative position and total momentum variables). We give the regularised forms of such tripartite EPR states in second-quantised formulation, and derive their Wigner functions. This is directly ...
متن کامل2 Fingerprints of entangled states in reactions with rare isotopes
We study the presence of entangled states of nucleon pairs from nuclear decays and in reactions with exotic nuclei, e.g., 11 Li, or 6 He. It is shown that the fingerprints of entangled states in these subsystems are visible in correlation measurements and can be accessed with present experimental techniques. This shows that not only atomic and optical systems, but also nuclear systems serve as ...
متن کامل