Squeezing on external degrees of freedom for atom interferometry

Atom interferomters are now reaching the standard quantum limit of phase estimation. This limit can be surpassed by implementing correlated (squeezed) atomic states as inputs to the interferometer. In this presentation I will show that it is possible, through a collective atomic measurement, to prepare such states for applications in interferometers with separated trajectories that measure inertial forces. A possible scheme using an optical cavity for probing on strontium atoms is illustrated and the squeezing limits are established. A method to cancel the cavity noise will also be proposed for this probing scheme.