 Superadditivity of quantum relative entropy

ID: superadditivity-of-quantum-relative-entropy

ρ_{A B}

and a product reference state,

D (ρ_{A B} ∥ σ_{A} \otimes σ_{B}) \geq D (ρ_{A} ∥ σ_{A}) + D (ρ_{B} ∥ σ_{B}) .

The difference between the two sides is the nonnegative quantum mutual information of

ρ_{A B}

 New to topics? Read the docs here!