About Superluminal Propagation of an Electromagnetic Wavepacket Inside a Rectangular Waveguide

We discuss the propagation of an electromagnetic wavepacket inside a rectangular waveguide, of the type employed in recent experiments on superluminal tunneling of electromagnetic signals. By exploiting the analogy between particle and photon tunneling, we consider both evanescent and growing waves inside the narrowed part of the waveguide. The Fourier expansion of such waves shows that the barrier behaves in a nonlocal way. Such a nonlocality is accounted for in an effective way by means of a deformation of the spacetime inside the waveguide. As a consequence, the wavepacket propagates at superluminal speed according to an effective metric tensor, built up in analogy with the Cauchy stress tensor in a deformable medium

Are particle and photon tunneling and filling in barriers local or non-local phenomena?

It is shown that particle and photon tunneling exhibits a non-local behaviour. This is also true for the wave filling in a semiclosed barrier with a dead stopper. In this connection, we discuss and define for the first time the penetration time of such a barrier in the wave-packet approach. (C) 2001 Elsevier Science B.V. All rights reserved

About superluminal propagation of an electromagnetic wavepacket inside a rectangular waveguide

We discuss the propagation of an electromagnetic wavepacket inside a rectangular waveguide, of the type employed in recent experiments on superluminal tunneling of electromagnetic signals. By exploiting the analogy between particle and photon tunneling, we consider both evanescent and growing waves inside the narrowed part of the waveguide. The Fourier expansion of such waves shows that the barrier behaves in a nonlocal way. Such a nonlocality is accounted for in an effective way by means of a deformation of the spacetime inside the waveguide. As a consequence, the wavepacket propagates at superluminal speed according to an effective metric tensor, built up in analogy with the Cauchy stress tensor in a deformable medium

TUNNELING TIME PROBLEM - MORE ABOUT THE TIME ANALYSIS OF TUNNELING PROCESSES - RESPONSE

In our recent review article [Phys. Rep. 214, 339 (1992)] we put forth an analysis of the main theoretical definitions of the sub-barrier tunnelling and reflection times, and proposed new definitions for such durations which seem to be self-consistent within conventional quantum mechanics. Very recently, in this Journal [Solid State Commun. 85, 115 (1993)], a paper by C.R. Leavens appeared claiming our definitions to be 'seriously flawed', on the basis of some numerical calculations for the average transmission times. We have nothing to object to those Leavens' calculations; except that they, simply, do not refer to our approach. In fact, they are based on equations different from the formulae proposed by us; in other words, Leavens' conclusions are valid for theories different from ours. We show in this note how further calculations, based on our own equations, do confirm that our approach is physically acceptable. Further criticism about our analysis of the dwell-time approaches is herein answered and commented.891313

Fourier-integral description of superluminal photon tunneling

We give a general Fourier-integral description of photon tunneling which can be applied either to electromagnetic waveguides and to optical devices. Moreover, pre extend to the case of frustrated total internal reflection our previous treatment of superluminal tunneling of evanescent waves in terms of a spacetime deformation

Multiple internal reflections during particle and photon tunneling

We discuss the time analysis of multiple internal reflections during one-dimensional tunneling of non-relativistic particles and photons with sub-barrier energies through potential barriers. The approach exploited is a simple analytic continuation from real (over-barrier) wave numbers to imaginary (sub-barrier) wave numbers. It is shown in particular that not only the general effective tunneling velocity, but also every effective transmission (tunneling) velocity for at least the first intermediate stage between successive internal reflections is superluminal. An interpretation of this seemingly strange fact is given in terms of an effective deformation of spacetime inside the barrier. The results obtained are interpreted with the help of the Fourier expansion over the virtual momentum space. A comparison with the instanton approach is also made

MORE ABOUT TUNNELING TIMES, THE DWELL TIME AND THE HARTMAN EFFECT

In a recent review paper [Phys. Reports 214 (1992) 339] we proposed, within conventional quantum mechanics, new definitions for the sub-barrier tunnelling and reflection times. Aims of the present paper are: i) presenting and analysing the results of various numerical calculations (based on our equations) on the penetration and return times , , during tunnelling inside a rectangular potential barrier, for various penetration depths x(f); ii) putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D tau(T). and D tau(R) for the time durations of transmission and reflection processes; nl) mentioning, moreover, that our definition for the average transmission time results to constitute an improvement of the ordinary dwell-time tau(DW) formula: iv) commenting, at last, on the basis of our new numerical results, upon some recent criticism by C.R. Leavens. We stress that our numerical evaluations confirm that our approach implied, and implies, the existence of the Hartman effect: an effect that in these days (due to the theoretical connections between tunnelling and evanescent-wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna - indirect, but quite interesting, experimental verifications. Eventully, we briefly analyze some other definitions of tunnelling times.5101351136