Related papers: Comments on Superluminal Photon Tunneling
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…
The tunneling time is here investigated by means of an electromagnetic model, for a system where a gap, between two parallel planes, acts as a classically-forbidden region for an impinging pulse with incidence angle larger than the critical…
Tunnelling transit time for a frustrated total internal reflection in a double-prism experiment was measured using microwave radiation. We have found that the transit time is of the same order of magnitude as the corresponding transit time…
A compact analysis of development and prospects in the study of the tunnelling evolution is given. A new systematization of various approaches to defining tunnelling times in the light of time as a quantum mechanical observable is proposed.…
Experiments with evanescent modes and tunneling particles have shown that i) their signal velocity may be faster than light, ii) they are described by virtual particles, iii) they are nonlocal and act at a distance, iv) experimental…
A unified approach to the time analysis of tunnelling of nonrelativistic particles is presented, in which Time is regarded as a quantum-mechanical observable, canonically conjugated to Energy. The validity of the Hartman effect…
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…
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…
In this review (in Italian) we critically and detaily examine various definitions existing in the literature for the tunnelling times: namely, the phase-time; the centroid-based times; the Buttiker and Landauer times; the Larmor times; the…
Tunnelling processes are thought to proceed via virtual waves due to observed superluminal (faster than light) signal speeds. Some assume such speeds must violate causality. These assumptions contradict, for instance, superluminally…
It is shown that the Hartman-Fletcher effect is valid for all the known expressions of the mean tunnelling time, in various nonrelativistic approaches, for the case of finite width barriers without absorption. Then, we show that the same…
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.…
We analyze the propagation of a pulse across a vacuum gap separating opposite flat parallel faces of two transparent dielectrics by means of an explicitly causal and retarded propagator constructed directly from the free-space wave…
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…
We exploit the analogy between tunnelling across a potential barrier and Aharonov's weak measurements to resolve the long standing paradox between the impossibility to exceed the speed of light and the seemingly 'superluminal' behaviur of…
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,…
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…
Experiments have shown that individual photons penetrate an optical tunnel barrier with an effective group velocity considerably greater than the vacuum speed of light. The experiments were conducted with a two-photon parametric…
Superluminal tunneling of light through a barrier has attracted broad interest in the last several decades. Despite the observation of such phenomena in various systems, it has been under intensive debate whether the transmitted light truly…
There have been several experiments which hint at evidence for superluminal transport of electromagnetic energy through a material slab. On the theoretical side, it has appeared evident that acausal signals are indeed possible in quantum…