Quantum-Spillover-Enhanced Surface-Plasmonic Absorption at the Interface of Silver and High-Index Dielectrics

Dafei Jin, Qing Hu, Daniel Neuhauser, Felix von Cube, Yingyi Yang, Ritesh Sachan, Ting S. Luk, David C. Bell, and Nicholas X. Fang

Phys. Rev. Lett. 115, 193901 – Published 3 November 2015

Abstract

We demonstrate an unexpectedly strong surface-plasmonic absorption at the interface of silver and high-index dielectrics based on electron and photon spectroscopy. The measured bandwidth and intensity of absorption deviate significantly from the classical theory. Our density-functional calculation well predicts the occurrence of this phenomenon. It reveals that due to the low metal-to-dielectric work function at such interfaces, conduction electrons can display a drastic quantum spillover, causing the interfacial electron-hole pair production to dominate the decay of surface plasmons. This finding can be of fundamental importance in understanding and designing quantum nanoplasmonic devices that utilize noble metals and high-index dielectrics.

Received 22 December 2014

DOI:https://doi.org/10.1103/PhysRevLett.115.193901

Authors & Affiliations

Dafei Jin¹, Qing Hu¹, Daniel Neuhauser², Felix von Cube³, Yingyi Yang¹, Ritesh Sachan⁴, Ting S. Luk⁵, David C. Bell³, and Nicholas X. Fang^1,*

¹Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
²Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California 90095, USA
³School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
⁴Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
⁵Sandia National Laboratory, Albuquerque, New Mexico 87123, USA