报告题目：Quantum continuous time crystals in dissipative Rydberg-atom arrays

报  告 人：Thomas Pohl（教授）

报告日期：2025年11月19日 星期三

报告时间：上午10：30-11：30

报告地点：激光光谱研究所三层报告厅

报告简介：

        Continuous time crystals, i.e., nonequilibrium phases with a spontaneously broken continuous time translational symmetry, have been studied and recently observed in the long-time dynamics of open quantum systems. In particular, experimental studies of strongly interacting thermal Rydberg gases have established that continuous time crystals (CTC) can emerge under the simultaneous optical driving of more than a single interacting Rydberg state. Motivated by these results, we discuss in this talk the dynamics in lattices of interacting Rydberg atoms, under optical two-photon driving with a standard three-level ladder configuration. While the emergence of continuous time-crystal phases in open quantum system as typically based on an underlying mean-field phenomenology, we focus here on their formation under conditions that do not a priory justify a simplified meanfield treatment [1]. Using complementary numerical methods we find two distinct time-crystal phases that cannot be described within mean-field theory. Remarkably, one of these quantum continuous time crystals (qCTCs) emerges only in the presence of quantum fluctuations. Our findings extend explorations of continuous time-translational symmetry breaking in dissipative systems beyond the classical phenomenology of periodic orbits in a low-dimensional nonlinear system. Possible experiments to observe the predicted qCTC phases in tweezer arrays of neutral atoms are also discussed.

报告人简介：

       Thomas Pohl，奥地利维也纳工业大学教授，主要研究方向为里德堡原子物理、量子非线性光学、量子多体物理等，曾担任丹麦国家研究基金会复杂量子系统研究中心主任、丹麦奥胡斯大学“尼尔斯-玻尔讲席教授”，迄今发表学术论文100余篇，其中Nature、Science、Nature子刊、PRL共50余篇，并长期担任上述期刊审稿人，目前总引用达1.1万余次，H因子56，受邀在国际专业会议进行学术报告100余次。