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 results on our upcoming investigations into evaporative cooling.

 

[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).