Invited speaker: About the concept of quantum information

OLIMPIA LOMBARDI

San Pablo

Workshop; South American Workshop on the Foundations of Quantum Theory and Cosmology; 2014

International Centre for Theoretical Physics

The elucidation of the concept of quantum information combines the difficulties inherent in understanding the meaning of the word ´information´ with the well-known foundational puzzles derived from quantum mechanics itself. This situation contrasts with the huge development of the research field named ´quantum information´. In the present work I will address the question ´What is quantum information?´ from a conceptual viewpoint. For this purpose, first Schumacher´s formalism will be introduced by contrast with Shannon´s theory, and the definition of quantum information in terms of a quantum source will be discussed. Then, the definition of information in terms of coding theorems will be analyzed. These tasks lead us to focus on the relationship between Shannon entropy and von Neumann entropy, and to discuss the differences between the concepts of bit and qubit. Finally, on the basis of the previous discussions, I will analyze the different interpretations of the concept of information, in the search of a characterization adequate both to Shannon´s and to Schumacher´s formalisms.