This talk will introduce our recent joint theory and experiment work on nonequilibrium dynamics in Rydberg atom ensembles. In the first part, we study nontrivial dynamics of Rydberg atoms driven by superradiance. An ensemble of excited atoms can synchronize the emission of light collectively in a process known as superradiance when its characteristic size is smaller than the wavelength of emitted photons. The underlying superradiance depends strongly on electromagnetic fields surrounding the atomic ensemble. We show, both theoretically and experimentally, that the van der Waals interactions between Rydberg atoms change the superradiant dynamics and modify the scaling of the superradiance. In the second part, we study nonequilibrium dynamics of an atom ensemble where Rydberg atom interactions, laser coupling and dissipation compete. A series of stationary phases, including uniform, antiferromagnetic, oscillatory, and bistable phases are obtained. Recent experiments have interpretated the oscillatory phase as synchronization, or dissipative time crystal. However the oscillation phase is not possible due to the random distribution of the atoms. We show that the oscillation is due to the formation of Rydberg excitation clusters, where these atoms are dynamically active. The quasi-regular structure of the active atoms allows the long-term oscillations.
报告人简介：李伟斌,诺丁汉大学物理与天文学院副教授，博士导师。本科和博士分别就读于华中科技大学和中科院武汉物理与数学研究所。主要从事里德堡原子物理和量子光学和量子模拟等的研究，在Science,Nature,Nature Communications, Science Advances, Phys. Rev. X和Phys. Rev. Lett.等国际刊物上发表100多篇论文。主持和承担欧盟、英国等多项科研项目。2010年获得欧盟玛丽-居里学者，2013年获得诺丁汉高等研究学者资助。担任Science,Phys.Rev.Lett.,Phys. Rev. X等学术杂志审稿人，兼任Scientific Reports的editorial board member和 Frontiers in Physics的associate editor。
报告地点：理学楼 822
报告时间： 2024.12.28 下午：2：00
