Universal nonlinear entanglement witnesses
Marcin Kotowski, Michał Kotowski, Marek Kuś · Physical Review A · 2010
We give a universal recipe for constructing nonlinear entanglement witnesses able to detect nonclassical correlations in arbitrary systems of distinguishable and/or identical particles for an arbitrary number of constituents. The constructed witnesses are expressed in terms of expectation values of observables. As such, they are, at least in principle, measurable in experiments.