%0 Journal Article
%A Capel, Angela
%A Lucia, Angelo
%A Pérez García, David
%T Superadditivity of Quantum Relative Entropy for General States
%D 2017
%@ 4758-4765
%U https://hdl.handle.net/20.500.14352/93365
%X The property of superadditivity of the quantum relative entropy states that, in a bipartite system H AB = H A ⊗ H B , for every density operator ρ AB , one has D(ρ AB ||σ A ⊗ σ B )≥ D(ρ A ||σ A ) + D(ρB||σB). In this paper, we provide an extension of this inequality for arbitrary density operators σ AB . More specifically, we prove that α(σ AB )· D(ρ AB ||σ AB )≥D(ρ A ||σ A )+ D(ρ B ||σ B ) holds for all bipartite states ρ AB and σ AB , where α(σ AB ) = 1 + 2||σ A -1/2 ⊗ σ AB σ A -1/2 ⊗ σ B -1/2 - || AB || ∞ .
%~