When do additional quantum noises affect controller performance?

Abstract

The introduction of quantum noise in a system is necessary for realizing it as physical quantum system. In general, quantum noise can be detrimental to the performance of a coherent quantum feedback control system. This paper gives a necessary and sufficient condition for when a quantum system corresponding to a given Linear Time Invariant (LTI) controller can be made physically realizable in the presence of both direct feedthrough quantum vacuum noise and additional quantum vacuum noise such that the additional quantum noise has no effect on the controller output. Furthermore, an example is presented to illustrate our result. Show more