Large-momentum-transfer Bragg interferometer with strontium atoms

We report on the first atom interferometer based on Bragg diffraction in a fountain of alkaline-earth atoms, namely ${}^{88}$Sr. We demonstrate large momentum transfer to the atoms up to eight photon recoils and the use of the interferometer as a gravimeter with a sensitivity $\delta g\mathrm{/}g=4\times {10}^{-8}$. Thanks to the special characteristics of strontium atoms for precision measurements, this result opens a new way for experiments in fundamental and applied physics.