Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5377261 | Chemical Physics | 2006 | 5 Pages |
Abstract
The purity, Tr(Ï2), measures how pure or mixed a quantum state Ï is. It is well known that quantum dynamical semigroups that preserve the identity operator (which we refer to as unital) are strictly purity-decreasing transformations. Here, we provide an almost complete characterization of the class of strictly purity-decreasing quantum dynamical semigroups. We show that in the case of finite-dimensional Hilbert spaces, a dynamical semigroup is strictly purity-decreasing if and only if it is unital, while in the infinite dimensional case, unitality is only sufficient.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
D.A. Lidar, A. Shabani, R. Alicki,