>VITAE:
David Vitali is associate professor of Physics at the University of Camerino since 2001.
His research interests are focused onto quantum optics and quantum information.
In more detail he is studying atomic and optical implementations of quantum computation and and quantum comunication protocols.
Other important research topics are decoherence control and quantum mechanical limits to high-sensitivity measurement.

We propose a Ramsey interferometry experiment able to reach the Heisenberg limit for the estimation of an atomic phase shift.
The scheme involves an ensemble of circular Rydberg atoms which together cross and dispersively interact with two microwave cavities.
The scheme does not require very high-Q cavities and an experimental realization with about ten entangled Rydberg atoms is achievable with state of art apparatuses.