Long baseline clock atom interferometry for gravitational wave and dark matter detection
Atom interferometry and atomic clocks continue to make impressive gains in sensitivity and time precision. I will discuss the potential for using atomic sensors for gravitational wave detection and searches for dark matter. Interest in this has driven the growth of the emerging field of long-baseline atomic sensing, which aims to scale up “tabletop” experiments to the kilometer-scale and beyond. Key to this is the development of a new type of “clock” atom interferometry based on narrow-line optical transitions that combines inertial sensitivity with features from the best atomic clocks. This technique is central to the MAGIS-100 experiment, a 100-meter-tall atomic sensor now under construction at Fermilab that will probe for ultra-light dark matter and will serve as a prototype for a future gravitational wave detector targeting the unexplored “mid-band” frequency range. Reaching the sensitivity needed for these ambitious goals also requires substantial advances in atom optics in order to increase the space-time area of the interferometer. I will describe atom optics that use Floquet modulation to reach pulse fidelities exceeding 99.4%, allowing for a record-setting momentum separation between the interferometer arms of over 400 ћk.