We are working on a method to realise the creation of squeezed momentum states that can be used for atom interferometry. The idea behind the method is to perform a probing measurement on a narrow transition in the dispersive regime inside a ring cavity, such that we measure the relative population of the two momentum states. The goal is to use this method to reach an interferometer phase scaling of N^(-3/4), therefore surpassing the standard quantum limit of $N^{-1/2}$