Majorization entropic uncertainty relations

Autorzy Puchała Z.; Rudnicki Ł.; Życzkowski K.
Tytuł Majorization entropic uncertainty relations
Czasopismo J. Phys. A: Math. Theor.
Rok 2013
Status Published
Tom 46
Strony 272002
Abstrakt Entropic uncertainty relations in a finite dimensional Hilbert space are investigated. Making use of the majorization technique we derive explicit lower bounds for the sum of Renyi entropies describing probability distributions associated with a given pure state expanded in eigenbases of two observables. The bounds obtained are expressed in terms of the largest singular values of submatrices of the unitary rotation matrix. For a generic unitary matrix of size N = 5 the bound obtained is stronger than the one of Maassen and Uffink (MU) with probability larger than 98%, and this ratio increases with N. We show also that the bounds investigated are invariant for unitary matrices equivalent up to dephasing and permutation and derive a classical analogue of the MU uncertainty relation formulated for stochastic transition matrices.