主讲人：邵灿 副教授（南京理工大学）

题目：High-Harmonic Generation Approaching the Quantum Critical Point of Strongly Correlated Systems

时间：2023年07月25日（周二）上午10：00

地点：理工楼1226报告厅

联系人：罗洪刚、陆汉涛

报告摘要：

By employing the exact diagonalization method, we investigate the high-harmonic generation (HHG) of the correlated systems under the strong laser irradiation. For the extended Hubbard model on a periodic chain, HHG close to the quantum critical point (QCP) is more significant compared to two neighboring gapped phases (i.e., charge-density-wave and spin-density wave states), especially in low frequencies. We confirm that the systems in the vicinity of the QCP are supersensitive to the external field and more optical-transition channels via excited states are responsible for HHG. This feature holds the potential of obtaining high- efficiency harmonics by making use of materials approaching QCP. Based on the two-dimensional Haldane model, we further propose that the even- or odd-order components of generated harmonics can be promisingly regarded as spectral signals to distinguish the topologically ordered phases from locally ordered ones. Our findings in this Letter pave the way to achieve ultrafast light source from HHG in strongly correlated materials and to study quantum phase transition by nonlinear optics in strong laser fields.

参考文献：

[1]C. Shao et al., Phys. Rev. Lett. 128, 047401 (2022).

个人简介：

邵灿2012年本科毕业于兰州大学物理科学与技术学院，同年进入兰州大学交叉学科中心跟随罗洪刚教授和陆汉涛教授从事强关联电子体系中非平衡动力学的研究，并于2017年获得博士学位。随后，他在北京计算科学研究中心从事博士后研究工作，主要从事强关联拓扑体系平衡和非平衡态的研究，2020年博士后出站进入南京理工大学，工作至今。