New Quantum Limits in Plasmonic Devices

TL;DR

This paper investigates quantum effects in surface plasmon polaritons at nanoscales, revealing fundamental size limits for plasmonic devices due to quantum damping effects even without collisional losses.

Contribution

It introduces a quantum model for SPPs at electron plasma-dielectric interfaces, highlighting quantum broadening as a key factor affecting plasmon damping.

Findings

Quantum broadening causes non-zero damping of SPPs without collisions.

Fundamental size limit for plasmonic devices due to quantum effects.

Quantum effects become significant at nanoscales approaching quantum regimes.

Abstract

Surface plasmon polaritons (SPPs) have recently been recognized as an important future technique for microelectronics. Such SPPs have been studied using classical theory. However, current state-of-the-art experiments are rapidly approaching nanoscales, and quantum effects can then become important. Here we study the properties of quantum SPPs at the interface between an electron quantum plasma and a dielectric material. It is shown that the effect of quantum broadening of the transition layer is most important. In particular, the damping of SPPs does not vanish even in the absence of collisional dissipation, thus posing a fundamental size limit for plasmonic devices. Consequences and applications of our results are pointed out.