Inhibition of Decoherence due to Decay in a Continuum

We propose a scheme for slowing down decay into a continuum. We make use of a sequence of ultrashort $2\pi$ pulses applied on an auxiliary transition of the system so that there is a destructive interference between the two transition amplitudes—one before the application of the pulse and the other after the application of the pulse. We give explicit results for a structured continuum. Our scheme can also inhibit unwanted transitions.