Equivalence regimes for geometric quantum discord and local quantum uncertainty

The concept of quantum discord aims at unveiling correlations that go beyond those described by entanglement. Its original formulation [J. Phys. A 34, 6899 (2001); Rev. Lett 88, 017901 (2002)] is difficult to compute even for the simplest case two-qubits systems. Alternative formulations have been developed address this drawback, such as geometric measure [Phys. 87, 062303 (2013)] and local uncertainty 110, 240402 can be evaluated in closed form some systems, two-qubit We show here these two measures are equivalent 2 x D dimensional bipartite By considering relevant example N00N states phase estimation lossy environments, we also both metrics quantify decrease Fisher information protocol. Given their ease computation demonstrate relevance computable discord.