Bipartite entanglement measure based on covariance
Isabel Sainz Abascal, Gunnar G. Bjork · Physical Review A · 2007
We propose an entanglement measure for two quNits based on the covariances of a set of generators of the $\mathrm{su}(N)$ algebra. In particular, we represent this measure in terms of the mutually unbiased projectors for $N$ prime. For pure states this measure quantifies entanglement, we obtain an explicit expression which relates it to the concurrence hierarchy, specifically the $I$-concurrence and the three-concurrence. For mixed states we propose a separability criterion.