Debunking van Enk-Pike's criterion for quantum games

Photons in polychromatic rotating modes

S. J. van Enk and G. Nienhuis Department of Physics, University of Oregon, Oregon Center for Optics and Institute for Theoretical Science Eugene, Oregon 97403, USA Institute for Quantum Information, California Institute of Technology, Pasadena, California 91125, USA Huygens Laboratorium, Universiteit Leiden, Postbus 9504, 2300 RA Leiden, The Netherlands Received 23 July 2007; published 19 Novem...

Experimental procedures for entanglement verification

S. J. van Enk, N. Lütkenhaus, and H. J. Kimble Department of Physics, Oregon Center for Optics and Institute for Theoretical Science, University of Oregon, Eugene, Oregon 97403, USA Institute for Quantum Information, California Institute of Technology, Pasadena, California 91125, USA Institute of Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontari...

Characterizing entanglement sources

We discuss how to characterize entanglement sources with finite sets of measurements. The measurements do not have to be tomographically complete and may consist of POVMs rather than von Neumann measurements. Our method yields a probability that the source generates an entangled state as well as estimates of any desired calculable entanglement measures, including their error bars. We apply two ...

When quantum tomography goes wrong: drift of quantum sources and other errors

The principle behind quantum tomography is that a large set of observations—many samples from a ‘quorum’ of distinct observables—can all be explained satisfactorily as measurements on a single underlying quantum state or process. Unfortunately, this principle may not hold. When it fails, any standard tomographic estimate should be viewed skeptically. Here we propose a simple way to test for thi...

Quantum and Atom Optics