an:06901132
Zbl 1393.15037
Ga??l, Marcell; Nagy, Gerg??
Transformations on density operators preserving generalised entropy of a convex combination
EN
Bull. Aust. Math. Soc. 98, No. 1, 102-108 (2018).
00408100
2018
j
15A86 15A60
entropy; quantum state; preserver; convex combination
Summary: We aim to characterise those transformations on the set of density operators (which are the mathematical representatives of the states in quantum information theory) that preserve a so-called generalised entropy of \textit{one} fixed convex combination of operators. The characterisation strengthens a recent result of \textit{M. Karder} and \textit{T. Petek} [Linear Algebra Appl. 532, 86--98 (2017; Zbl 1370.15028)] where the preservation of the same quantity was assumed for \textit{all} convex combinations.
Zbl 1370.15028