Optimal Bounds on Functions of Quantum States under Quantum Channels

Chi-Kwong Li, Diane Christine Pelejo, Kuo-Zhong Wang

Let ${\rho }_1,{\rho }_2$ be quantum states and $({\rho }_1,{\rho }_2)\mapsto D({\rho }_1,{\rho }_2)$ be a scalar function such as the trace norm, the fidelity, and the relative entropy, etc. We determine optimal…