Eur. Phys. J. D (2013) 67: 62
https://doi.org/10.1140/epjd/e2013-30647-y

Regular Article

Time-ordering dependence of measurements in teleportation

University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090 Vienna, Austria

^a e-mail: Reinhold.Bertlmann@univie.ac.at

Received: 20 October 2012
Received in final form: 28 January 2013
Published online: 21 March 2013

Abstract

We trace back the phenomenon of “delayed-choice entanglement swapping” as it was realized in a recent experiment to the commutativity of the projection operators that are involved in the corresponding measurement process. We also propose an experimental set-up which depends on the order of successive measurements corresponding to noncommutative projection operators. In this case entanglement swapping is used to teleport a quantum state from Alice to Bob, where Bob has now the possibility to examine the noncommutativity within the quantum history.