- Kapitsa-Dirac effect
The Kapitsa-Dirac effect is a quantum mechanical effect consisting in the diffraction of a well-collimatedclarifyme particle beam (often an
electron beam), by astanding wave of light. [ cite journal|title=The Kapitza-Dirac effect|journal=Contemporary Physics|date=November 2000|first=H|last=Batelaan|coauthors=|volume=41|issue=6|pages=369–381|id= |doi= 10.1080/00107510010001220 | url=http://www.informaworld.com/smpp/title~content=t713394025 |format=|accessdate=2008-07-07 ] The effect was first predicted byPaul Adrien Maurice Dirac andPyotr Kapitsa in 1933. [ cite journal|title=|journal=Proc Cambridge Phil Soc|date=1933|first=P. L.|last=Kapitza|coauthors=P. A. M. Dirac|volume=29|issue=|pages=297|id= |url=|format=|accessdate=2008-07-07 ]The effect is explained by the
wave-particle duality , as stated by thede Broglie hypothesis in 1924. As a consequence of the wavelike nature of particles, a coherent beam of particles should be diffracted by the spatially periodicelectromagnetic field structure set up by a standingelectromagnetic wave , and should interfere with itself (the intensity of the particle beam should vary in with distance, presenting several maxima and minima, like in opticaldiffraction pattern s).A highly-coherent light beam is required for the realization of the experiment, and couldn't be realized before the invention of
laser s. The most effective experiment that show the expected diffraction peaks was carried out in 2001. cite book|author=S. Gasiorowicz |title=Quantum physics |edition=3rd Edition |publisher=John Wiley & Sons |year=2003 |isbn=0-471-05700-2]References
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