Related papers: Comment on: Testing the speed of 'spooky action at…
In this Letter, we present a cosmic Bell experiment with polarization-entangled photons, in which measurement settings were determined based on real-time measurements of the wavelength of photons from high-redshift quasars, whose light was…
Relativistic invariance is a physical law verified in several domains of physics. The impossibility of faster than light influences is not questioned by quantum theory. In quantum electrodynamics, in quantum field theory and in the standard…
An explanation for superluminal phenomena based on wave-particle duality of photons is suggested. A single photon may be regarded as a wave packet, whose spatial extension is its coherence volume. As a photon propagates as a wave train in…
Numerical implementation of a theory yields acoustic wave packets whose peak-to-peak speeds, $c_{3d}$, are supersonic in a dispersionless medium due to temporal interference between direct and boundary-reflected paths. The effect occurs…
An experimental test of Bell's inequality allows ruling out any local-realistic description of nature by measuring correlations between distant systems. While such tests are conceptually simple, there are strict requirements concerning the…
No causal paradoxes will occur if a preferred reference frame for tachyons propagation is assumed, and results of Bell's inequality experiments may be well explained without using any telepathyc effect. We can read G. Faraci's and others'…
The mechanisms leading to a seemingly superluminal propagation of light in dispersive media are examined. The anomalous dispersion near an absorption line, involved in the first experiments displaying negative group velocity propagation, is…
The title of this article is misleading. The authors have investigated a resonator but not a tunneling barrier see also Refs.\cite{Winful2} The measured superluminal group velocity and discussed is that studied on a Lorentz-Lorenz…
All paradoxes concerning faster-than-light signal propagation reported in recent experiments can be dispelled by using imaginary time in a quantum framework. I present a proposal of testing imaginary time in a total reflection.
A recent paper published in Am. J. Phys. describes an experiment designed to measure the one-way speed of light. Although the experiment is very interesting, in particular to be used in student laboratories, it is in fact determining the…
Demonstrations of quantum entanglement which confirm the violation of Bell's inequality indicate that under certain conditions action at a distance is possible. This consequence seems to contradict the relativistic principle of causality,…
Experimentally fixed sound pulse beyond of light speed in the region of anomalous dispersion [W. M. Robertson, e. a. Appl. Phys. Lett, 90, 014102 (2007)] can be explained, as well as the similar superluminal phenomena, by "the nonlocality…
In this article, a procedure called Probabilistic Swapped-Bell-States Analysis (PSBA) is proposed. Using this procedure two communication partners can transmit (binary-encoded) information over large spatial distances. This procedure is…
When the boundary condition of a quantum system changes, how fast will it affect the state of the system? Here we show that if the response takes place immediately, then it can allow superluminal signal transfer. Else if the response…
We report the first experimental realization of entanglement swapping over large distances in optical fibers. Two photons separated by more than two km of optical fibers are entangled, although they never directly interacted. We use two…
Establishing reliable quantum links between a network of satellites and ground stations is a crucial step towards realizing a wide range of satellite-based quantum protocols, including global quantum networks, distributed sensing, quantum…
We present a Bell-type polarization experiment using two independent sources of polarized optical photons, and detecting the temporal coincidence of pairs of uncorrelated photons which have never been entangled in the apparatus. Very…
Contemporary observational and theoretical studies on the temporal nature of microscopic measurements renewed the discussion about the fundamental constants, leading to the possibility of light speed variation and superluminal pulse…
Quantum communication relies on the efficient generation of entanglement between remote quantum nodes, due to entanglement's key role in achieving and verifying secure communications. Remote entanglement has been realized using a number of…
A single photon incident on a beam splitter produces an entangled field state, and in principle could be used to violate a Bell-inequality, but such an experiment (without post-selection) is beyond the reach of current experiments. Here we…