Strong in-plane scattering of acoustic graphene plasmons by surface atomic steps

Nature Communications

Lei Wang¹  Xinzheng Zhang²  Wei Wu²  Ni Zhang²  Weiwei Luo²  Jingjun Xu²  Jiang Fan²  Mengxin Ren²  Wei Cai³ 

[1] College of Physics and Electronic Engineering, Xinyang Normal University, 464000, Xinyang, China;The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, School of Physics and TEDA Institute of Applied Physics, Nankai University, 300457, Tianjin, China;The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, School of Physics and TEDA Institute of Applied Physics, Nankai University, 300457, Tianjin, China;Collaborative Innovation Center of Extreme Optics, Shanxi University, 030006, Taiyuan, Shanxi, China;

DOI  :  10.1038/s41467-022-28614-z

来源: Springer

【 摘 要 】

Acoustic graphene plasmons (AGPs) have ultrastrong field confinement and low loss, which have been applied for quantum effect exploration and ångström-thick material sensing. However, the exploration of in-plane scattering of AGPs is still lacking, although it is essential for the manipulation of ultraconfined optical fields down to atomic level. Here, by using scattering-type scanning near-field optical microscopy (s-SNOM), we show that the mid-infrared AGPs can be strongly scattered by atomic level height steps, even though the step height of the scatterer is four orders of magnitude smaller than the incident free wavelength. This effect can be attributed to larger back scattering of AGPs than that of the traditional graphene plasmons. Besides, the scattering of AGPs by individual scatterers can be controlled via electrical back gating. Our work suggests a feasible way to control confined optical fields with atomic level height nanostructures, which can be used for ultra-compacted strong light–matter interactions.

【 授权许可】

CC BY