Abstract: We have developed the Photon-Resolved Floquet Theory (PRFT), which besides predicting the state of a driven quantum system (e.g., the atom or molecule), can also predict the number of photons exchanged with the coherent driving field [1,2]. To this end, the PRFT introduces counting fields into the semiclassical equations of motions, that track the photons in the driving field. Interestingly, the PRFT predicts light-matter entanglement in the Floquet-state basis. This effect can be employed to devise a measurement-based quantum communication protocol, which has favorable scaling properties over long distances. We apply the PRFT to spectroscopy, where it can project the Fisher information of coherent spectroscopic signals [3]. As I will explain in my talk, the PRFT opens thus new paths to design and optimize quantum sensors based on AMO systems, which might assist in the discovery of new physics.

Bio: Georg Engelhardt received his PhD at the TU Berlin in 2017, after which he joined the BCSRC as a postdoctoral research fellow until 2021. At present, he works as an associate researcher at the Southern University of Science and Technology. He has published 18 Nature Index articles, including five articles in Physical Review Letters, that have received over 500 citations. He investigates principles of light-matter interaction in the quantum optical and semiclassical regimes. In this context, he develops protocols for quantum control and quantum sensing. Besides others, his research has contributed to the understanding of the polariton dynamics and the quantum control of Floquet systems.