报告题目：Calculating free-electron nonlinearities in nonclassical plasmonic heavily doped semiconductor systems

报告人：胡华天 研究员 （意大利技术研究院）

报告时间：2024年11月1日（星期五），15:00-16:00

报告地点：致知楼会议室 3328

报告摘要：

Understanding the nonlinear light-matter interaction at the nanoscale has been a long-standing fundamental target since it guides the design rule for minimized and integrated nonlinear photonic devices. Achieving a strong and ultrafast nonlinear optical response is essential for various fields such as optical information processing and artificial intelligence training. Yet, efficiently manipulating light with light is still challenging, leading to an urgent demand of exploring new physics for higher nonlinear interactions.

Free-electron dynamics have a substantial contribution to the optical nonlinearity in heavily doped semiconductor systems. We applied both frequency- and time-domain approaches based on the finite-element method to explore a significant third-harmonic generation and optical Kerr bistability. This high nonlinearity originates from the multibody properties of the free electron gas as the electron-electron interaction can be naturally taken into account in the hydrodynamic theory when proper kinetic energy functionals are considered. Supported by this free-electron nonlinearity, an optical bistability with low-power threshold of mW to uW level can be achieved.

报告人简介：

胡华天，意大利技术研究院研究员，2021年6月毕业于武汉大学高等研究院，获博士学位，在徐红星院士课题组从事贵金属等离激元与物质相互作用以及其光谱学相关研究。后在意大利技术研究院从事博士后工作，研究方向为非经典（非局域）等离激元体系中的非线性光学，在重掺杂半导体等离激元体系中开展了一系列理论以及实验工作。论文被引990余次，在Science, Nature family, Nano Letters, ACS Nano等期刊发表过多篇论文，本次报告主要内容以封面论文的形式被ACS Photonics期刊接收。