Foundations of Physics

, Volume 37, Issue 2, pp 295–305 | Cite as

Paradox in Wave-Particle Duality

  • Shahriar S. AfsharEmail author
  • Eduardo Flores
  • Keith F. McDonald
  • Ernst Knoesel

We report on the simultaneous determination of complementary wave and particle aspects of light in a double-slit type “welcher-weg” experiment beyond the limitations set by Bohr’s Principle of Complementarity. Applying classical logic, we verify the presence of sharp interference in the single photon regime, while reliably maintaining the information about the particular pinhole through which each individual photon had passed. This experiment poses interesting questions on the validity of Complementarity in cases where measurements techniques that avoid Heisenberg’s uncertainty principle and quantum entanglement are employed. We further argue that the application of classical concepts of waves and particles as embodied in Complementarity leads to a logical inconsistency in the interpretation of this experiment.


principle of complementarity wave-particle duality non- perturbative measurements double-slit experiment Afshar experiment 

PACS numbers:

03.65.Ta 42.50.Xa 14.70.Bh 


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Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Shahriar S. Afshar
    • 1
    Email author
  • Eduardo Flores
    • 1
  • Keith F. McDonald
    • 1
  • Ernst Knoesel
    • 1
  1. 1.Department of Physics & AstronomyRowan UniversityGlassboroUSA

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