报告人：Prof. Dr. Peter Hommelhoff

主持人：李辉 副研究员

时间：2021年10月15日（周五）下午15：00-17：00

地点：光学大楼B225，

Zoom会议ID：89340742142，密码468223

报告人简介：

Peter Hommelhoff教授，德国Erlangen大学激光物理首席教授，于2002年在德国慕尼黑大学获博士学位，师从诺贝尔物理学奖得主T. W. Hänsch教授。2003-2007年，在斯坦福大学从事博士后研究，2008-2012年在德国马普量子光学研究所担任研究组长。2012年开始，成为德国Erlangen大学全职教授，同期担任马克斯普朗克研究所MPL会员。Hommelhoff教授担任德国物理协会会员等职，曾获ERC杰出基金等众多项目支持、以及玛丽居里奖、洪堡奖学金等。Hommelhoff教授长期从事强场物理、超快物理等领域的研究，代表性工作包括微电子芯片上的BEC（Nature2001），纳米针尖光电子发射的阿秒调控（Nature2011），在石墨烯中实现电场驱动电流（Nature2017），固体界面内部光电子发射的阿秒测量（Nature Physics2020）等。共发表SCI论文200余篇，Google Scholar引用7000余次。

报告内容简介：

It is well known for decades that light can impart momentum to charged particles in the vicinity of a third body. With nanostructured dielectric materials and ultrafast laser pulses, this momentum transfer can become highly efficient, demonstrated in 2013 in two proof-of-concept experiments. Since then, not only acceleration has been shown but also deflection and focusing based purely on optical nearfield forces. With these ingredients at hand, we are now at a point to build an on-chip particle accelerator. Like in any accelerator, active beam confinement is as important as acceleration, in order not to lose particles while they are accelerated. For this, the alternating phase focusing scheme is employed in RF accelerators to keep a charged particle pulse well contained while it is accelerated. Alternating phase focusing relies on excellent electron phase space control, which is what we have achieved, at optical frequencies an in the 225-nm wide channel of an 80 micrometer long nanophotonic structure. In this talk, I will show the status of nanophotonics-based particle acceleration, including an outlook on applications of the particle accelerator on a chip, which is now within close reach. This work is part of the Moore Foundation-funded Accelerator on a Chip International Program - ACHIP.