Detecting and Quantifying Entanglement via Bayesian Updating

Understand

We show how a straightforward Bayesian updating procedure allows one to detect and quantify entanglement from any finite set of measurement results.

• The measurements do not have to be tomographically complete, and may consist of POVMs rather than von Neumann measurements.
• One obtains a probability that one's state is entangled and an estimate of any desired entanglement measure, including their error bars.
• As an example we consider (tomographically incomplete) spin correlation measurements on both 2-qubit and 3-qubit states.