Table of Contents
ISRN Mathematical Physics
Volume 2012 (2012), Article ID 327278, 37 pages
Research Article

Quantum Histories and Quantum Complementarity

Department of Psychiatry and Neurobiology, Graduate School of Medical Science, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa 920-8641, Japan

Received 6 August 2011; Accepted 27 September 2011

Academic Editor: F. Sugino

Copyright © 2012 Danko Georgiev. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We discuss the origin of quantum complementarity using Feynman's sum-over-histories approach to Quantum Mechanics (QM). We analyze two experimental setups introduced by W. G. Unruh and S. Afshar and show how one should consistently calculate the existence of which-way information using interfering quantum histories. Then we discuss the possible problems associated with the notion of which way information and provide an explanation why Englert-Greenberger duality relation cannot be violated experimentally if the standard QM postulates are accepted.