Quantum Correlations Beyond Entanglement

Abstract

A mixed state shared by two parties, Alice and Bob, is called classically correlated if it can be written as reported by Oppenheim (Physical Review Letters 89:180402, 2002) ρcc= ∑ ijpij| i⟩ ⟨ i| A⊗ | j⟩ ⟨ j| B, where { | i⟩ A} are orthogonal states on Alice’s Hilbert space HA and { | j⟩ B} are orthogonal states on Bob’s Hilbert space HB.