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The Afshar Two-Slit Experiment and Complementarity

Kastner, Ruth (2005) The Afshar Two-Slit Experiment and Complementarity. [Preprint]

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A modified version of Young's experiment by Shahriar Afshar demonstrates that, prior to a ``which-way'' measurement indicating which slit a particle goes through, an interference pattern exists. It has been claimed that this result constitutes a violation of the Principle of Complementarity. This paper discusses the implications of this experiment and considers how Cramer's Transactional Interpretation accomodates the result. It is shown that the Afshar experiment is isomorphic in key respects to a a spin one-half particle prepared as ``spin up along x'' and post-selected in a specific state of spin along z. It is concluded that Bohr would have had no more problem accounting for the Afshar result than he would in accounting for the aforementioned pre- and post-selection spin experiment, in which the particle's preparation state is confirmed by a nondestructive measurement prior to post-selection.

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Item Type: Preprint
Kastner, Ruth
Additional Information: The Afshar experiment is often dismissed on the basis that the wire grid acts as a "diffraction grating" which scatters photons. This argument is incorrect, nor does Unruh make this argument in his rebuttal of claims by Afshar regarding his experiment. This author is in substantial agreement with Unruh's conclusions regarding the Afshar experiment.
Keywords: transactional, time symmetry, two-slit, complementarity
Subjects: Specific Sciences > Physics > Quantum Mechanics
Depositing User: Ruth E. Kastner
Date Deposited: 05 Feb 2005
Last Modified: 07 Oct 2010 15:13
Item ID: 2187
Subjects: Specific Sciences > Physics > Quantum Mechanics
Date: February 2005

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