Particle Path Through a Nested Mach-Zehnder Interferometer
Abstract
Possible paths of a photon passing through a nested Mach-Zehnder interferometer on its way to a detector are analyzed using the consistent histories formulation of quantum mechanics, and confirmed using a set of weak measurements (but not weak values). The results disagree with an analysis by Vaidman [ Phys.\ Rev.\ A 87 (2013) 052104 ], and agree with a conclusion reached by Li et al.\ [ Phys.\ Rev.\ A 88 (2013) 046102 ]. However, the analysis casts serious doubt on the claim of Salih et al.\ (whose authorship includes Li et al.) [ Phys.\ Rev.\ Lett.\ 110 (2013) 170502 ] to have constructed a protocol for counterfactual communication: a channel which can transmit information even though it contains a negligible number of photons.
Cite
@article{arxiv.1604.04596,
title = {Particle Path Through a Nested Mach-Zehnder Interferometer},
author = {Robert B. Griffiths},
journal= {arXiv preprint arXiv:1604.04596},
year = {2016}
}
Comments
18 pages, 1 figure. Minor revisions have been made to produce a manuscript accepted for publication in Phys. Rev. A