Resonant purification of mixed states for closed and open quantum systems
Raffaele Romano · Physical Review A · 2007
Pure states are fundamental for the implementation of quantum technologies, and several methods for the purification of the state of a quantum system $S$ have been developed in the past years. In this work we describe a mechanism leading to purification of mixed states, based on the interaction of $S$ with an auxiliary system $P$. Considering two-level systems and assuming a particular interaction between them, we study how the dynamical parameters of the system $P$ affect the purification of $S$. By using analytical and numerical tools, we show that the purification process exhibits a resonant behavior in both the cases of system isolated from the external environment or not.