UNIGE document Scientific Article
previous document  unige:4261  next document
add to browser collection
Title

Time Dependence of Evanescent Quantum Waves

Authors
Muga, J.G.
Published in Physical Review. A. 2000, vol. 62, no. 2, p. 023808
Abstract The time dependence of quantum evanescent waves generated by a point source with an infinite or a limited frequency band is analyzed. The evanescent wave is characterized by a forerunner (transient) related to the precise way the source is switched on. It is followed by an asymptotic, monochromatic wave which at long times reveals the oscillation frequency of the source. For a source with a sharp onset the forerunner is exponentially larger than the monochromatic solution and a transition from the transient regime to the asymtotic regime occurs only at asymptotically large times. In this case, the traversal time for tunneling plays already a role only in the transient regime. To enhance the monochromatic solution compared to the forerunner we investigate (a) frequency band limited sources and (b) the short time Fourier analysis (the spectrogram) corresponding to a detector which is frequency band limited. Neither of these two methods leads to a precise determination of the traversal time. However, if they are limited to determine the traversal time only with a precision of the traversal time itself both methods are successful: In this case the transient behavior of the evanescent waves is at a time of the order of the traversal time followed by a monochromatic wave which reveals the frequency of the source.
Identifiers
Full text
Structures
Citation
(ISO format)
MUGA, J.G., BUTTIKER, Markus. Time Dependence of Evanescent Quantum Waves. In: Physical Review. A, 2000, vol. 62, n° 2, p. 023808. https://archive-ouverte.unige.ch/unige:4261

218 hits

458 downloads

Update

Deposited on : 2009-11-30

Export document
Format :
Citation style :