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Decoherence and Vacuum Fluctuations a
Author(s) -
FORD L. H.
Publication year - 1995
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.1995.tb39015.x
Subject(s) - physics , quantum decoherence , electron , photon , quantum fluctuation , electromagnetic field , amplitude , quantum electrodynamics , casimir effect , quantum mechanics , interference (communication) , coupling (piping) , quantum optics , observable , vacuum energy , quantum , mechanical engineering , channel (broadcasting) , electrical engineering , engineering
The interference pattern of coherent electrons is effected by coupling to thequantized electromagnetic field. The amplitudes of the interference maxima arechanged by a factor which depends upon a double line integral of the photontwo-point function around the closed path of the electrons. The interferencepattern is sensitive to shifts in the vacuum fluctuations in regions from whichthe electrons are excluded. Thus this effect combines aspects of both theCasimir and the Aharonov-Bohm effects. The coupling to the quantizedelectromagnetic field tends to decrease the amplitude of the interferenceoscillations, and hence is a form of decoherence. The contributions due tophoton emission and to vacuum fluctuations may be separately identified. It isto be expected that photon emission leads to decoherence, as it can revealwhich path an electron takes. It is less obvious that vacuum fluctuations alsocan cause decoherence. What is directly observable is a shift in thefluctuations due, for example, to the presence of a conducting plate. In thecase of electrons moving parallel to conducting boundaries, the dominantdecohering influence is that of the vacuum fluctuations. The shift in theinterference amplitudes can be of the order of a few percent, so experimentalverification of this effect may be possible. The possibility of using thiseffect to probe the interior of matter, e.g., to determine the electricalconductivity of a rod by means of electrons encircling it is discussed.(Presented at the Conference on Fundamental Problems in Quantum Theory,University of Maryland, Baltimore County, June 18-22, 1994.)Comment: 7pp +2 Figs.(not included), TUTP-94-1