Experiments in Many-body Cavity QED: Entangled Matterwave Interferometers, Superradiant Lasers, and Dynamical Phase Transitions
Prof. James Thompson (JILA; University of Colorado, Dept. of Physics, Boulder/USA)

I will discuss a range of cavity QED experiments that explore how to exploit atom-light interactions to create atom-atom correlations and entanglement for quantum sensing and quantum simulation. Using rubidium atoms, we have implemented both cavity-enhanced quantum nondemolition measurements and cavity-mediated spin-spin interactions to realize an entangled light-pulse matterwave interferometer that is directly observed to operate below the standard quantum limit [1]. Using strontium atoms, we have achieved pulsed superradiant lasing on the millihertz clock transition [2,3], developed a new method for determining the intrinsic radiative lifetime of the clock state [4], and observed a dynamical phase transition [5] arising from a competition between cavity-mediated spin exchange interactions [6] and single particle dynamics. If time permits, I will briefly describe our progress toward a continuous superradiant laser.

[1] Greve & Luo et al, arXiv:2110.14027 (2021)
[2] Norcia et al, Science Adv. 2 e1601231 (2016)
[3] Norcia et al, Phys. Rev. X 8 021036 (2018)
[4] Muniz et al, Phys. Rev. Res. 3 023152 (2021)
[5] Muniz et al, Nature 580 602 (2020)
[6] Norcia et al, Science 361 259 (2018)