Particle simulation of plasmons

Nanophotonics

article

Wen Jun Ding¹  Lin Wu¹  Jeremy Zhen Jie Lim²  Hue Thi Bich Do³  Xiao Xiong¹  Zackaria Mahfoud⁵  Ching Eng Png¹  Michel Bosman⁴  Lay Kee Ang² 

[1] Agency for Science, and Research (A*STAR), Institute of High Performance Computing;SUTD-MIT International Design Center and Science and Math Cluster, Singapore University of Technology and Design (SUTD);NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore;Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1;Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR)

关键词: particle-in-cell;    particle simulation;    plasmas;    plasmons;    spill-out effects;   

DOI  :  10.1515/nanoph-2020-0067

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Particle simulation has been widely used in studying plasmas. The technique follows the motion of a large assembly of charged particles in their self-consistent electric and magnetic fields. Plasmons, collective oscillations of the free electrons in conducting media such as metals, are connected to plasmas by very similar physics, in particular, the notion of collective charge oscillations. In many cases of interest, plasmons are theoretically characterized by solving the classical Maxwell’s equations, where the electromagnetic responses can be described by bulk permittivity. That approach pays more attention to fields rather than motion of electrons. In this work, however, we apply the particle simulation method to model the kinetics of plasmons, by updating both particle position and momentum (Newton–Lorentz equation) and electromagnetic fields (Ampere and Faraday laws) that are connected by current. Particle simulation of plasmons can offer insights and information that supplement those gained by traditional experimental and theoretical approaches. Specifically, we present two case studies to show its capabilities of modeling single-electron excitation of plasmons, tracing instantaneous movements of electrons to elucidate the physical dynamics of plasmons, and revealing electron spill-out effects of ultrasmall nanoparticles approaching the quantum limit. These preliminary demonstrations open the door to realistic particle simulations of plasmons.

【 授权许可】

CC BY