Position-controlled quantum emitters with reproducible emission wavelength in hexagonal boron nitride

Clarisse Fournier,Julien Barjon,Kenji Watanabe,Jean-Pierre Hermier,Sébastien Roux,Stéphanie Buil,Michael Rosticher,Aurélie Pierret,Takashi Taniguchi,Xavier Quélin,Aymeric Delteil,Alexandre Plaud

doi:10.1038/s41467-021-24019-6

Abstract

Single photon emitters (SPEs) in low-dimensional layered materials have recently gained a large interest owing to the auspicious perspectives of integration and extreme miniaturization offered by this class of materials. However, accurate control of both the spatial location and the emission wavelength of the quantum emitters is essentially lacking to date, thus hindering further technological steps towards scalable quantum photonic devices. Here, we evidence SPEs in high purity synthetic hexagonal boron nitride (hBN) that can be activated by an electron beam at chosen locations. SPE ensembles are generated with a spatial accuracy better than the cubed emission wavelength, thus opening the way to integration in optical microstructures. Stable and bright single photon emission is subsequently observed in the visible range up to room temperature upon non-resonant laser excitation. Moreover, the low-temperature emission wavelength is reproducible, with an ensemble distribution of width 3 meV, a statistical dispersion that is more than one order of magnitude lower than the narrowest wavelength spreads obtained in epitaxial hBN samples. Our findings constitute an essential step towards the realization of top-down integrated devices based on identical quantum emitters in 2D materials.

Highlights

Single photon emitters (SPEs) in low-dimensional layered materials have recently gained a large interest owing to the auspicious perspectives of integration and extreme miniaturization offered by this class of materials
Quantum emission is associated with point defects that were long thought to be of the intrinsic kind, carbon impurities have been shown to play a role in the structure of at least part of the observed SPEs10
We use high purity hexagonal boron nitride (hBN) synthesized at high pressure, high temperature (HPHT)[25], of which we exfoliate single flakes of a few tens of nanometres thickness on a silicon substrate, either with or without a top 285 nm SiO2 layer

Summary

Introduction

Single photon emitters (SPEs) in low-dimensional layered materials have recently gained a large interest owing to the auspicious perspectives of integration and extreme miniaturization offered by this class of materials. The considerable variety of impacted fields of physics[1,2] has been including solid-state quantum optics[3] since the discovery of single photon emission in WSe24–8 and hBN9 In the latter material, quantum emission is associated with point defects that were long thought to be of the intrinsic kind, carbon impurities have been shown to play a role in the structure of at least part of the observed SPEs10. The SPEs appear in most cases at random locations in the crystal, often preferentially close to the flake edges[19] Effort towards controlling their position has included the use of focused ion beam[20], as well as strain through exfoliation on patterned substrates[21], but the emitters obtained with these methods exhibit large variations in their number, emission wavelength and optical properties. Our work paves the way to top-down fabrication of integrated devices based on SPEs in hBN

Methods

Results

Conclusion