Alexander Lvovsky

Abstract:

The preparation and characterization of a new quantum state of light, a coherent superposition of the single-photon and vaccum states was discussed. This state was generalized by a catalytic process in which the single photon state enabled the interaction without being affected. A transition between a highly classical and a highly nonclassical state of light occurred by changing the amplitude of the target coherent state.

Abstract:

We report preparation and characterization of coherent superposition states t[0>+alpha]1> of the electromagnetic field by conditional measurements on a beam splitter. This state is generated in one of the beam splitter output channels if a coherent state [alpha> and a single-photon Fock state [1> are present in the two input ports and a single photon is registered in the other beam splitter output. The single photon thus plays a role of a "catalyst:" it is explicitly present in both the input and the output channels of the interaction yet facilitates generation of a nonclassical state of light.