Copper plasmonics with excitons

TL;DR

This paper explores how strong excitons in copper oxide influence surface plasmon propagation in copper layers, enabling long-range plasmons that mitigate copper's high ohmic losses, with analytical and numerical validation.

Contribution

It demonstrates the impact of Cu$_2$O excitons on copper plasmonics and shows how thin copper layers can support long-range plasmons to reduce losses.

Findings

Strong excitons in Cu$_2$O significantly affect plasmon propagation.

Thin copper layers can excite long-range plasmons (LRSPPs).

Analytical results are validated by numerical calculations.

Abstract

We investigate the propagation of surface plasmons (SPPs) in a thin layer of copper surrounded by copper oxide Cu$_2$O. It is shown that particularly strong excitons in Cu$_2$O can have considerable impact on plasmon propagation, providing many opportunities for plasmon-exciton and plasmon-plasmon interactions. It is demonstrated that by the use of sufficiently thin metal layer, one can excite the so-called long range plasmons (LRSPPs) which can overcome the inherently high ohmic losses of Cu as compared to usual plasmonic metals such as silver. Analytical results are confirmed by numerical calculations.