Hopping of single nanoparticles trapped in a plasmonic double-well potential

Nanophotonics

article

Seung Ju Yoon¹  Da In Song¹  Jungmin Lee¹  Myung-Ki Kim²  Yong-Hee Lee¹  Chang-Kyu Kim³ 

[1] Department of Physics, Korea Advanced Institute of Science and Technology (KAIST);KU-KIST Graduate School of Converging Science and Technology, Korea University;Department of Nano & Semiconductor Engineering, Korea Polytechnic University

关键词: Arrhenius factor;    double-well potential;    Kramers hopping;    nanoantenna;    plasmonics;   

DOI  :  10.1515/nanoph-2020-0411

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Thermally induced particle hopping in the nanoscale double-well potential is fundamental in material design and device operation. After the proposal of the basic hopping theory, several experimental studies, including some using the optical trapping method, have validated the theoretical approach over various friction ranges of the surrounding medium. However, only external parameters, such as viscosity, temperature, and pressures, have been varied in practical circumstances, and other tools capable of adjusting the potential profile itself to modulate the hopping rate are needed. By using metallic nanoantenna with various gap sizes and different optical pump power, we engineered a double-well potential landscape and directly observed the hopping of a single nanoparticle with a diameter of 4 nm. The distance between the two potential wells was 0.6–5 nm, and the maximum well depth and maximum height of the central potential barrier were approximately 69 and 4  k B T , respectively. The hopping rate was governed by the Arrhenius law and showed a vertex when the barrier height was approximately 2  k B T , which was in good agreement with the computational expectations.

【 授权许可】

CC BY