Disorder-Engineered Hybrid Plasmonic Cavities for Emission Control of Defects in hBN

TL;DR

This paper presents a scalable, low-cost method to enhance and control emission from defect-based quantum emitters in hBN using hybrid plasmonic nanocavities, achieving up to 100-fold photoluminescence enhancement.

Contribution

The study introduces a scalable fabrication approach for hybrid plasmonic nanocavities with hBN emitters, enabling significant emission enhancement without deterministic positioning.

Findings

Hybrid nanocavities provide up to 100-fold PL enhancement.

AgNPs on bare hBN yield two-fold PL enhancement.

Size-dependent control over decay dynamics confirmed by FDTD and PL measurements.

Abstract

Defect-based quantum emitters in hexagonal boron nitride (hBN) are promising building blocks for scalable quantum photonics due to their stable single-photon emission at room temperature. However, enhancing their emission intensity and controlling the decay dynamics remain significant challenges. This study demonstrates a low-cost, scalable fabrication approach to integrate plasmonic nanocavities with defect-based quantum emitters in hBN nanoflakes. Using the thermal dewetting process, we realize two distinct configurations: stochastic Ag nanoparticles (AgNPs) on hBN flakes and hybrid plasmonic nanocavities formed by AgNPs on top of hBN flakes supported on gold/silicon dioxide (Au/SiO2) substrates. While AgNPs on bare hBN yield up to a two-fold photoluminescence (PL) enhancement with reduced emitter lifetimes, the hybrid nanocavity architecture provides a dramatic, up to 100-fold PL enhancement and improved uniformity across multiple. emitters, all without requiring deterministic positioning. Finite-difference time-domain (FDTD) simulations and time-resolved PL measurements confirm size-dependent control over decay dynamics and cavity-emitter interactions. Our versatile solution overcomes key quantum photonic device development challenges, including material integration, emission intensity optimization, and spectral multiplexity. Future work will explore potential applications in integrated photonic circuits hosting on-chip quantum systems and hBN-based label-free single-molecule detection through such quantum nanoantennas.