Conditional evolution in single-atom cavity QED
Andrei N. Soklakov, Rüdiger Schack · Physical Review A · 2001
We consider a typical setup of cavity QED consisting of a two-level atom interacting strongly with a single resonant electromagnetic-field mode inside a cavity. The cavity is resonantly driven and the output undergoes continuous homodyne measurements. We derive an explicit expression for the state of the system conditional on a discrete photocount record. This expression takes a particularly simple form if the system is initially in the steady state. As a byproduct, we derive a formula for the steady state that had been conjectured before in the strong driving limit.