Atom interferometry with large momentum transfer

The sensitivity of light-pulse atom interferometers can be greatly improved by large momentum transfer (LMT) beam splitters and long interrogation times. Large momentum space separation $\Delta $p between two interferometric arms result in increased phase shift proportional to $\Delta $p or even ($\Delta $p)$^{2}$, and therefore leads to superior tools for precision measurements. ``BBB'' beam splitters, using high order Bragg diffraction combined with Bloch oscillations, have already been demonstrated and are scalable, as their momentum transfer is not limited by the available laser power. By running an additional conjugate interferometer at the same time, noises common to both interferometers can be eliminated. We will present our work aiming at further improvements, which would allow applications requiring extremely large enclosed areas, such as test of the Einstein equivalence principle, measurements of fundamental constants, or searching for new gravitational effects.