JILA Wannier-Stark Lattice Clock part II – Physics: Simultaneous Clock Operation and Gravimetry in an Optical Lattice Clock

The exquisite measurement precision of optical clocks and matterwave interferometers independently offer exciting opportunities to probe fundamental physics and gravity. In this talk, we present a trapped atom interferometer scheme [1] implemented via simultaneous interrogation of the clock and motional degrees of freedom within a ⁸⁷Sr Wannier-Stark Lattice clock. Specifically, we perform clock spectroscopy at lattice depths less than ten photon recoils with the optical local oscillator detuned from the clock transition by +/- m g a , where a is the lattice spacing, m the Sr mass, and g the local gravitational acceleration. This process prepares a coherent superposition of both the internal clock states and the external Wannier-Stark states, which will generally lead to stronger collisional frequency shifts and decoherence due to s-wave collisions between atoms occupying distinguishable internal states on the same lattice site [2, 3]. To control these shifts and extend coherence, we prepare atoms on strictly alternating lattice sites by using an optical super lattice during state preparation. We will present our current measurement results.