近日，华东师范大学吴健团队研究了激子极化子的飞秒相干动力学。2025年11月19日出版的《国家科学评论》杂志发表了这一最新研究成果。

激子极化激元可作为宏观量子相干性的理想载体，其特性有望通过精确调控驱动激光场来实现操控。然而，目前关于泵浦激光与强耦合光-物质系统之间相干特性关联的研究尚不充分。

研究组通过干涉测量法，首次可视化呈现了飞秒量级下激光场相干性向共振激发的激子极化激元的传递动力学。研究发现，共振极化激元能在飞秒时间尺度内有效维持泵浦激光场的相干性。在强激发条件下，能量更高的非共振极化激元会延迟数皮秒出现，且不继承泵浦光的相位相干性，该现象可通过耦合振子模型得到合理解释。该研究为通过精细调控外部泵浦激光场来调节极化激元相干性提供了新途径。

附：英文原文

Title: Femtosecond coherence dynamics of exciton polaritons

Author: Jia, Haoyuan, Cao, Junhui, Chen, Fei, Peng, Fangying, Li, Yihui, Xu, Yihan, Chen, Leizhu, Ye, Ziyu, Zhao, Xianyan, Zhang, Shian, Jing, Jietai, Xu, Hongxing, Chen, Zhanghai, Byrnes, Tim, Li, Hui, Kavokin, Alexey, Wu, Jian

Issue&Volume: 2025-11-19

Abstract: Exciton-polariton performs as an ideal carrier of macroscopic quantum coherence, which can be potentially manipulated through precisely shaping the driving laser field. However, the connection of the coherence properties between the pumping laser and the strongly-coupled light-and-matter system is studied to a lesser extent. In this paper, we visualize the femtosecond dynamics of coherence transfer from the driven laser field to the resonantly excited exciton polariton by an interferometric measurement. The resonant polaritons can effectively preserve the coherence of the pumping laser field in femtosecond time scales. At a high excitation strength, non-resonant polaritons appear at higher energies delayed by several picoseconds, without the phase coherence from the pump, which is understood by a coupled oscillator model. Our results offers the possibility to regulate the polarition coherence by finely shaping the external pump laser fields.

DOI: 10.1093/nsr/nwaf493

Source: https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwaf493/8327612searchresult=1