Workshop on QUANTUM INFORMATION PROCESSING AND QUANTUM COMMUNICATIONS

Quantum Mechanics: Axiomatics of Measurements and connections with Computing and Information Retrieval

Information Extraction versus Disturbance in Quantum Theory: an Information Theoretic Approach

aula DOTTORATO - VENERDI' 2 NOVEMBRE ore 11.00
  FRANCESCO BUSCEMI , University of Pavia - Italy

>PRESENTATION: Francesco Buscemi completed his PhD in Physics at the University of Pavia in 2006, under the supervision of Prof. G. M. D'Ariano, with the thesis "Optimization and Realization of Quantum Devices". Since May 2006 he's researcher at the "ERATO-SORST Quantum Computation and Information Project", funded by the Japan Science and Technology Agency, and is affiliated with the Graduate School of Information Science at Tokyo University.

Francesco Buscemi
Abstract  
  We describe the information balance in a general quantum measuring process, and provide, as a byproduct, a sound information-disturbance tradeoff. In particular, we extend the notion of coherent information from the case of quantum channels to the more general case of quantum measurements, and show that such a quantity can accurately describe the disturbance that a quantum measurement unavoidably causes on the input system, whenever some useful information is extracted. The single-outcome case, that is, the case of measurements with post-selection, is finally discussed.
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