Collective interactions between resonant nuclei offer new opportunities to explore nonlinear quantum optics at x-ray energies. In this talk, I will present our recent theoretical studies of multiphoton x-ray emission and superradiant bursts in nuclear ensembles. First, using matrix product states combined with quantum trajectories, we investigate excitation-dependent emission dynamics and photon statistics, revealing nonlinear effects beyond the weak-excitation approximation. We then establish the conditions for generating superradiant x-ray bursts and uncover nonlinear relationships between the initial excitation number, peak time, and peak intensity. These results provide new insights into cooperative many-body dynamics and offer guidance for future experiments with x-ray free-electron lasers.

Biography

Yue Chang is an associate researcher at the Beijing Academy of Quantum Information Sciences. She received her PhD from the Institute of Theoretical Physics, Chinese Academy of Sciences, and subsequently conducted postdoctoral research at the Max Planck Institute of Quantum Optics. Her current research focuses on quantum optics and its applications to quantum precision measurement, Rydberg-atom ensembles, X-ray quantum optics, and few-photon scattering.

Inviter: Ying-Dan Wang