Quantum Information Theory : To Clarify New Information Processings Assisted by Quantum Effects and Their Performance Limits

Abstract

Conventional information theory is based on mathematical modeling of information processing by physical entities obeying the law of classical physics. This modeling is, however, an incomplete approximation, and information theory should eventually be reconstructed according to the more basic principle, quantum mechanics. The studies in this direction has been initiated in 60's, and much accelerated since 90's. This new theory, quantum information theory, is to clarify new information processings assisted by quantum effects and their performance limits while naturally comprehending conventional theory. In this article, its basic notions and open problems are reviewed from the viewpoint of communication theory.