Microscopic derivation of the one qubit Kraus operators for amplitude and phase damping

This article presents microscopic derivation of the Kraus operators for (the generalized) amplitude and phase damping process. Derivation is based on the recently developed method [Andersson et al, J. Mod.Opt. 54, 1695 (2007)] which concerns finite dimensional systems (e.g. qubit). The form of these operators is usually estimated without insight into the microscopic details of the dynamics. The behavior of the qubit dynamics is simulated and depicted via Bloch sphere change.