讲座名称：Electron Emission and Nano Plasma in Nanogap for compact THz sources

讲座时间：2026年9月10日 下午 3:00-5:00

报告人：Lay Kee Ang教授  新加坡科技设计大学

校区：西安交通大学创新港校区

讲座地点：创新港躬行楼（3号巨构）3-6001

邀请人：孟国栋教授

Title: Electron Emission and Nano Plasma in Nanogap for compact THz sources

Time：10^th September 2026，3:00-5:00.pm.

Venue：3-6001，Gongxing Building，I-harbor campus

Speaker：Professor Lay Kee Ang, Singapore University of Technology and Design, Singapore

Inviter：Professor Guodong Meng

报告摘要：Electron emission and nanoplasmas in nanogaps constitute an emerging research field that bridges vacuum nanoelectronics, ultrafast electronics, plasma physics, and quantum transport. When electrode separations shrink to tens of nanometers or below, classical vacuum electronics, field emission, quantum tunneling, and plasma formation become strongly coupled, producing physics that does not exist in conventional models. Depending on the size of the gap spacing, the mechanism is also depending on the medium in between the nanogap – such as vacuum, gas or solid. For gap spacing ranging from 0.5 to 5 nm, quantum tunneling dominates for the bulk transport. For 10s nm, tunneling (field emission and others) from the electrode is important for the formation of nanoplasmas. For a micro-gap at a few microns – the formation of nano-plasmas will be governed by the so called modified Paschen law. The transition regime between the nano-gap to micro-gap is of interests not only for consistent modeling linking in different spatial dimension, but for many applications. Compared to steady-state discharge condition, time-dependent dynamics (less studied) of the electrons and the plasmas can be used to produce THz emission. In this talk, I will give a short overview of the status of this research and report some recent works. For applications, we focus on relatively high-power terahertz (THz) sources using nano plasmas in collaborations with our collaborators. We utilize Particle-in-Cell (PIC) simulations to investigate gas discharge dynamics under atmospheric pressure in a nanogap. We systematically analyze the effect of external resistance, emission area, and gap spacing on plasma formation and the dynamical processes leading to steady-state behavior. Notably, as the gap spacing is reduced to 100 nm and below , the breakdown voltage deviates from the predictions of the modified Paschen’s law. These results provide insights into nanoscale plasma dynamics, informing the design and optimization of future nano-plasma devices

报告人简介：Prof. Lay Kee (Ricky) Ang received his MSc and PhD degrees from the University of Michigan, USA. He is currently the Associate Provost (Research and International Relations), Ng Teng Fong Chair Professor, and Professor of Science, Mathematics and Technology in the Singapore University of Technology and Design (SUTD). Before joining SUTD, he was a professor in the Division of Microelectronics, School of EEE, Nanyang Technological University, Singapore (2002-2011), and a LANL director postdoctoral fellow (1999-2001) in the Applied Physics division, Los Alamos National Laboratory (LANL). His current research interests are in the theoretical formulation of electron emission, charge transport, electrical contact, and light-matter interaction for applications in electronics, photonics and plasmas. For modeling, he is currently applying fractional calculus to analyze complicated and disordered systems. His research projects were/are funded by Singapore (MOE, ASTAR, SUTD) and USA (AFOSR and ONRG). He is a fellow of 4 technical societies (APS, IEEE, IOP and AAIA). He is a IEEE Distinguished Lecturer and Top 2% Scientist in Applied Physics. He is now also (a) Qiushi Quest Professor (Zhejiang University); (b) Distinguished Visiting Professor (Tsinghua University) and (c) Adjunct Professor (Xi’an Jiaotong University).