Maximally entangled mixed states and conditional entropies

Abstract

The maximally entangled mixed states of Munro [Phys. Rev. A 64, 030302 (2001)] are shown to exhibit interesting features vis á vis conditional entropic measures. The same happens with the Ishizaka and Hiroshima states [Phys. Rev. A 62, 022310 (2000)], whose entanglement degree cannot be increased by acting on them with logic gates. Special types of entangled states that do not violate classical entropic inequalities are seen to exist in the space of two qubits. Special meaning can be assigned to the Munro special participation ratio of 1.8. © 2005 The American Physical Society.