Coupling emission from single localized defects in 2D semiconductor to surface plasmon polaritons

TL;DR

This paper demonstrates a method to efficiently couple localized defect emissions in a 2D semiconductor to surface plasmon polaritons in a silver nanowire, achieving a coupling efficiency of at least 39%, which advances quantum photonics applications.

Contribution

The study introduces a self-aligned technique to couple single defect emitters in 2D materials to plasmonic modes with high efficiency, overcoming nanometer positioning challenges.

Findings

Achieved at least 39% coupling efficiency from defect to plasmonic mode.

Localized defect sites are formed via strain induced by a silver nanowire.

Demonstrated a scalable method for coupling 2D semiconductor defects to plasmonics.

Abstract

Coupling of an atom-like emitter to surface plasmons provides a path toward significant optical nonlinearity, which is essential in quantum information processing and quantum networks. A large coupling strength requires nanometer-scale positioning accuracy of the emitter near the surface of the plasmonic structure, which is challenging. We demonstrate the coupling of single localized defects in a tungsten diselenide (WSe2) monolayer self-aligned to the surface plasmon mode of a silver nanowire. The silver nanowire induces a strain gradient on the monolayer at the overlapping area, leading to the formation of localized defect emission sites that are intrinsically close to the surface plasmon. We measure a coupling efficiency with a lower bound of 39% from the emitter into the plasmonic mode of the silver nanowire. This technique offers a way to achieve efficient coupling between plasmonic structures and localized defects of 2D semiconductors.