Global information balance in quantum measurements.
We perform an information-theoretical analysis of quantum measurement processes and obtain the global information balance in quantum measurements, in the form of a closed chain equation for quantum mutual entropies. Our balance provides a tight and general entropic information-disturbance trade-off, and explains the physical mechanism underlying it. Finally, the single-outcome case, that is, the case of measurements with posts election, is briefly discussed.
ERATO-SORST Quantum Computation and Information Project, Japan Science and Technology Agency, Tokyo, 113-0033, Japan. buscemi@qci.jst.go.jp
Francesco
F
Buscemi
Masahito
M
Hayashi
Michał
M
Horodecki