Speaker: Alexander Holevo (Steklov Mathematical Institute of RAS)
Date: Nov. 24 (Friday)
Beijing time: 15:00-16:00 (Moscow time: 10:00-11:00)
Zoom ID: 818 0023 9961 Password: 507448
Abstract：
Quantum information theory studies the laws for transmission, transformation and storage of information in the systems obeying rules of quantum physics. One of its major achievements is creation and thorough investigation of the concept of quantum communication channel which resulted in elaborated structural theory and was accompanied by discovery of a whole spectrum of entropic quantities characterizing information-processing performance of the channels.
The topic of this lecture – the capacity of quantum channel for transmitting classical information – is intended to make a bridge between the classical and quantum theories and is especially convenient for a smooth transition to the latter. On the other hand, being the earliest and perhaps the most mature part of quantum Shannon theory, this topic continues to develop actively. Several recent achievements reflected in this lecture, as well as intriguing open questions, concern this range of problems.
First we introduce a basic notion of classical-quantum channel as a channel with classical input and quantum output, and give a brief survey of a variety of the relevant results. Next, we discuss the general concept of quantum channel, its algebraic structure and the classical capacities, and touch upon the remarkable quantum phenomenon of superadditivity of information in memoryless channels due to entanglement in the decoding and encoding procedures. We then describe quantum Gaussian channels and report on the progress concerning the noncommutative analogs of the famous Shannon capacity formula resulting from recent contributions to the solution of the long-standing “quantum Gaussian optimizer conjecture”.
Biography:
Prof. Holevo received the Ph.D. degree in physics-math sciences in 1969, and Habilitation in physics-math sciences in 1975. He is a Soviet and Russian mathematician, one of the pioneers of quantum information science. He was elected as a Corresponding Member of the Russian Academy of Sciences in 2016 and a Full Member in 2019. His list of publications contains over 200 titles, including five monographs, four of them translated into English and published by AMS, North Holland, Springer-Verlag, and DeGruyter. His scientific interests include noncommutative probability, quantum information and statistical decision theory, and mathematical foundations of quantum theory.