Progress toward atomic force sensor to detect Bloch oscillations from surrounding forces*

We present an atomic force sensor that will use non-destructive measurement techniques to probe interactions between Yb and external forces over second time scales. Yb atoms are loaded into a crossed optical dipole trap using a far detuned optical dipole trap and an optical cavity lattice to be evaporatively cooled. Once the atoms reach ground state degeneracy, we turn off the far-detuned trap so that the atoms remain in the shallow in-vacuum optical cavity. The atoms, remaining trapped in the optical cavity, experience coherent Bloch oscillations due to surrounding forces and will oscillate at frequencies proportional to those surrounding forces. Using a non-destructive measurement technique, we will monitor the wavefunction of the trapped atoms to observe the Bloch oscillations in real time [1]. The extended trap time of the experiment allows continuous measurements to look for time-varying forces. New fields, such as ultra-light dark matter, can create oscillating forces which would be detected through oscillations in the Bloch frequency [2]. For large Compton frequencies, the dark matter signal would appear as side bands on the gravitational Bloch frequency peak in frequency space. We present progress towards the development of a precision force sensor.

[1] R.D. Niederriter, C. Schulpf, and P. Hamilton, “Cavity probe for real-time detection of atom dynamics in an optical lattice”, Physical Review A 102, 051301 (2020).

[2] A. Arvanitaki, J. Huang, and K. Van Tilburg, “Searching for dilaton dark matter with atomic clocks”, Physical Review D 91, 015015 (2015).