Overview of the Experimental Procedure

Jacob P. Covey

Monika Aidelsburger

Cheng-An Chen

S. J. van Enk, Norbert Lütkenhaus, Harry J. Kimble

We give an overview of different types of entanglement that can be generated in experiments, as well as of various protocols that can be used to verify or quantify entanglement. We propose several criteria that, we argue, should be applied to experimental entanglement verification procedures. Explicit examples demonstrate that not following these criteria will tend to result in overestimating the amount of entanglement generated in an experiment or in inferring entanglement when there is none. We distinguish protocols meant to refute or eliminate hidden-variable models from those meant to verify entanglement.

Ulf Leonhardt, Henryk Paul

An overview is given on experimental schemes for measuring phase properties (in particular, phase distributions) discussed and partly even realized thus far. It is pointed out that all of them amount to measuring the Q function for the field. Moreover, experimental procedures for determining the Wigner function for the field more or less directly are described which thus allow to assign experimental significance to the concept of area of overlap in phase space when applied to the quantum mechanical description of phase.

Julien Spahn