01028nas a2200157 4500000000100000008004100001100001700042700002200059700002100081700002200102245006000124856005100184300001100235490000700246520061700253 2014 d1 aŁ. Rudnicki1 aZbigniew Puchała1 aPaweł Horodecki1 aKarol Życzkowski00aConstructive entanglement test from triangle inequality uhttps://doi.org/10.1088/1751-8113/47/42/424035 a4240350 v473 a

We derive a simple lower bound on the geometric measure of entanglement for mixed quantum states in the case of a general multipartite system. The main ingredient of the presented derivation is the triangle inequality applied to the root infidelity distance in the space of density matrices. The obtained bound leads to entanglement criteria with a straightforward interpretation. The proposed criteria provide an experimentally accessible, powerful entanglement test. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to '50 years of Bell's theorem'.