EPL, 83 (2008) 60006
DOI: 10.1209/0295-5075/83/60006

Entanglement witnesses from single-particle interference

T. Scholak^{1, 2}, F. Mintert^{2, 3} and C. A. Müller<sup>1

1</sup>   Physikalisches Institut, Universität Bayreuth - 95440 Bayreuth, Germany, EU
²   Physikalisches Institut, Albert-Ludwigs-Universität Freiburg - 79104 Freiburg, Germany, EU
³   Max-Planck-Institut für Physik Komplexer Systeme - Nöthnitzerstraße 38, 01187 Dresden, Germany, EU

torsten.scholak@physik.uni-freiburg.de

received 22 April 2008; accepted in final form 29 July 2008; published September 2008
published online 10 September 2008

Abstract
We describe a general method of realizing entanglement witnesses in terms of the interference pattern of a single quantum probe. After outlining the principle, we discuss specific realizations both with electrons in mesoscopic Aharonov-Bohm rings and with photons in standard Young's double-slit or coherent-backscattering interferometers.

PACS
03.67.Mn - Entanglement measures, witnesses, and other characterizations.
73.23.-b - Electronic transport in mesoscopic systems.
42.25.Hz - Interference.

© EPLA 2008