  We experimentally demonstrate a shaken lattice interferometer. Atoms are
trapped in the ground Bloch state of a red-detuned optical lattice. Using a
closed-loop optimization protocol based on the dCRAB algorithm, we
phase-modulate (shake) the lattice to transform the atom momentum state. In
this way, we implement an atom beamsplitter and build five interferometers of
varying interrogation times $T_I$. The sensitivity of shaken lattice
interferometry is shown to scale as $T_I^2$, consistent with simulation [1].
Finally, we show that we can measure the sign of an applied signal and optimize
the interferometer in the presence of a bias signal.
  [1] C. A. Weidner, H. Yu, R. Kosloff, and D. Z. Anderson, Phys. Rev. A 95,
043624 (2017).
