Qubit Entanglement Breaking Channels

Mary Beth Ruskai

Published 2003-02-04, updated 2003-06-04Version 3

This paper continues the study of stochastic maps, or channels, which break entanglement. We give a detailed description of entanglement-breaking qubit channels, and show that such maps are precisely the convex hull of those known as classical-quantum channels. We also review the complete positivity conditions in a canonical parameterization and show how they lead to entanglement-breaking conditions.