1. dynamical control of phases and time crystal in an atom-photon sytem

Jayson Cosme

University of the Philippines, Philippines

25 February 2021 Thu 4 pm

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

Periodic driving of strongly correlated systems has led to outstanding discoveries from manipulation of equilibrium properties like in light-enhanced superconductivity, to the creation of genuine dynamical states, such as time crystals. To gain insights into the nature of these phenomena, we have recently studied the effects of external periodic driving in a well-controlled yet versatile many-body platform consisting of ultracold atoms coupled to the light field of a high-finesse optical cavity. In this system, structures in both space and time may emerge due to the rich interplay between driving, dissipation, and long-range atomic interaction mediated by the cavity photons. In this talk, I will discuss the full dynamical phase diagram of the periodically driven atom-cavity system. For off-resonant driving, we observe dynamical control of the self-organisation phase transition. While for resonant driving, we discover the emergence of genuine nonequilibrium phases, namely a discrete time crystalline phase and dynamical density wave orders. Accompanying experimental results confirm our theoretical predictions of light-induced control in the atom-cavity system.