Approximation of Reachable Set for Coherently Controlled Open Quantum Systems: Application to Quantum State Engineering

摘要

Precisely characterizing and controlling realistic open quantum systems isone of the most challenging and exciting frontiers in quantum sciences andtechnologies. In this Letter, we present methods of approximately computingreachable sets for coherently controlled dissipative systems, which is veryuseful for assessing control performances. We apply this to a two-qubit nuclearmagnetic resonance spin system and implement some tasks of quantum control inopen systems at a near optimal performance in view of purity: e.g., increasingpolarization and preparing pseudo-pure states. Our work shows interesting andpromising applications of environment-assisted quantum dynamics.