Abstract. The goal of this article is to provide a largely self-contained introduction to the modelling of controlled quantum systems under continuous observation, and to the design of feedback controls that prepare particular quantum states. We describe a bottom-up approach, where a field-theoretic model is subjected to statistical inference and is ultimately controlled. As an example, the formalism is applied to a highly idealized interaction of an atomic ensemble with an optical field. Our aim is to provide a unified outline for the modelling, from first principles, of realistic experiments in quantum control.

Keywords: quantum feedback control, quantum state preparation, quantum probability, quantum filtering, continuous measurement

Print publication: Issue 10 (October 2005)
Received 29 April 2005, accepted for publication 15 July 2005
Published 14 September 2005