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Research in Optical Sciences

Complementarity Revisited

Wolfgang P. Schleich

Published Jan 1, 2012• 0 citations
Publisher

Abstract

We analyze two recent double-slit experiments using twin photons demonstrating the simultaneous observation of “which-slit” information and interference. They suggest new aspects of Niels Bohr’s principle of complementarity.
DOI
10.1364/qim.2012.qw2b.6

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A detailed analysis of Einstein's version of the double-slit experiment, in which one tries to observe both wave and particle properties of light, is performed. Quantum nonseparability appears in the derivation of the interference pattern, which proves to be surprisingly sharp even when the trajectories of the photons have been determined with fairly high accuracy. An information-theoretic approach to this problem leads to a quantitative formulation of Bohr's complementarity principle for the case of the double-slit experiment. A practically realizable version of this experiment, to which the above analysis applies, is proposed.