Speaker: Tomohiro Ogawa (Univ. Electro Communications)

Title: On quantum channel coding theorem and coupling constants

Time/Date: 4:45-6:15pm, April 9 (Thu.), 2020

Room: 056

Abstract: The first part of this talk is devoted to review quantum channel coding theorem by Devetak (2005) and its generalization. In quantum information theory, quantum error correcting codes have been studied for sending pure quantum states over noisy quantum channels (CPTP maps). Given a quantum channel, its channel capacity is defined as the supremum of asymptotically achievable transmission rates of quantum error correcting codes using multiple copy of the channel. The quantum channel coding theorem characterizes the quantum channel capacity as a certain limit of entropic quantity, so-called "coherent information." In the second part of the talk, we discuss some relations between the quantum channel capacity and coupling constants of II₁ factors.