Related papers: Causality and Electromagnetic Transmissions Throug…
Acausal features of quantum electrodynamic processes are discussed. While these processes are not present for the classical electrodynamic theory, in the quantum electrodynamic theory, acausal processes are well known to exist. For example,…
Contrary to mechanical waves, the two-slit interference experiment of single photons shows that the behavior of classical electromagnetic waves corresponds to the quantum mechanical one of single photons, which is also different from the…
This paper shows that ordinary quantum mechanics is not consistent with the superluminal transmission of classical information.
We prove that the classical Dirac equation in the presence of an external (nondynamical) electromagnetic field is a relativistically causal theory. As a corollary, we show that it is impossible to use quantum tunneling to transmit particles…
The paper elucidates the physical basis of experimental results on superluminal signal velocity. It will be made plausible that superluminal signals do not violate the principle of causality but they can shorten the luminal vacuum time span…
Photonic tunneling permits superluminal signal transmission. The principle of causality is not violated but the time duration between cause and effect can be shortened compared with an interaction exchange with velocity of light. This…
This is an analysis of some aspects of an old but still controversial topic, superluminal quantum tunneling. Some features of quantum tunneling described in literature, such as definition of the tunneling time and a frequency range of a…
Various experiments have shown superluminal group and signal velocities recently. Experiments were essentials carried out with microwave tunnelling, with frustrated total internal reflection, and with gain-assisted anomalous dispersion.…
Signal causality, the prohibition of superluminal information transmission, is the fundamental property shared by quantum measurement theory and relativity, and it is the key to understanding the connection between nonlocal measurement…
A simple relativistic analysis is presented which shows that near-field superluminal longitudinal electric signals generated by an electric dipole cannot be used to violate Einstein causality by using the relativistic "sync shift" effect.…
The apparent superluminal propagation of electromagnetic signals seen in recent experiments is shown to be the result of simple and robust properties of relativistic field equations. Although the wave front of a signal passing through a…
A recently proposed gedankenexperiment involving the (gravitational or electromagnetic) interaction between two objects--one placed in a state of quantum superposition of two locations--seems to allow for faster-than-light communication.…
It recently has been demonstrated that signals conveyed by evanescent modes can travel faster than light. In this report some special features of signals are introduced and investigated, for instance the fundamental property that signals…
Classical linear wave superposition produces the appearance of interference. This observation can be interpreted in two equivalent ways: one can assume that interference is an illusion because input components remain unperturbed, or that…
Apparently 'superluminal' transmission, e.g., in quantum tunnelling and its variants, occurs via a subtle interference mechanism which allows reconstruction of the entire spacial shape of a wave packet from its front tail. It is unlikely…
This paper shall define and discuss two types of quantum process - Disentangling and Entangling. The first type will be shown to contradict Unitarity and is therefore ruled out as a possible signalling process within standard linear Quantum…
By relativity we show that, although the superluminal motion of classical particles is forbidden, the superluminal transportation of quanta of any massive matter field is possible. Exact theoretical derivation and precise numerical…
In the present work we investigate the possibility of superluminal information transmission in quantum theory. We give simple and general arguments to prove that the general structure (Hilbert's space plus instantaneous state reduction) of…
Though both theoretical and experimental investigations have revealed the superluminal behavior of evanescent electromagnetic waves, there are many disputes about the physical meaning and validity of such superluminal phenomenon, which is…
A relativistic quantum-mechanical description of guided waves is given, based on which we present an alternative way to describe and interpret the propagation of electromagnetic wave packets through an undersized waveguide. In particular,…