Nanoscale axial position and orientation measurement of hexagonal boron nitride quantum emitters using a tunable nanophotonic environment

TL;DR

This paper introduces a method to precisely measure the axial position and 3D orientation of single-photon emitters in thick hBN flakes by tuning their photonic environment with VO2, aiding quantum photonics integration.

Contribution

It presents a novel approach using tunable nanophotonics to determine emitter position and orientation in thick hBN, advancing characterization techniques for quantum emitters.

Findings

Emitters show a strong surface-normal dipole orientation.

The method enables systematic characterization of SPEs in hBN.

Optimized transfer technique for reproducible placement of flakes.

Abstract

Color centers in hexagonal boron nitride (hBN) have emerged as promising candidates for single-photon emitters (SPEs) due to their bright emission characteristics at room temperature. In contrast to mono- and few-layered hBN, color centers in multi-layered flakes show superior emission characteristics such as higher saturation counts and spectral stability. Here, we report a method for determining both the axial position and three-dimensional dipole orientation of SPEs in thick hBN flakes by tuning the photonic local density of states using vanadium dioxide (VO2), a phase change material. Emitters under study exhibit a strong surface-normal dipole orientation, providing some insight on the atomic structure of hBN SPEs, deeply embedded in thick crystals. We have optimized a hot pickup technique to reproducibly transfer flakes of hBN from VO2 onto SiO2/Si substrate and relocated the same emitters. Our approach serves as a practical method to systematically characterize SPEs in hBN prior to integration in quantum photonics systems.