Tunable and high-purity room temperature single-photon emission from atomic defects in hexagonal boron nitride

Abstract

Two-dimensional van der Waals materials have emerged as promising platforms for solid-state quantum information processing devices with unusual potential for heterogeneous assembly. Recently, bright and photostable single photon emitters were reported from atomic defects in layered hexagonal boron nitride (hBN), but controlling inhomogeneous spectral distribution and reducing multi-photon emission presented open challenges. Here, we demonstrate that strain control allows spectral tunability of hBN single photon emitters over 6 meV, and material processing sharply improves the single photon purity. We observe high single photon count rates exceeding 7 × 106 counts per second at saturation, after correcting for uncorrelated photon background. Furthermore, these emitters are stable to material transfer to other substrates. High-purity and photostable single photon emission at room temperature, together with spectral tunability and transferability, opens the door to scalable integration of high-quality quantum emitters in photonic quantum technologies.

Strain-Tunable Single Photon Sources in WSe2 Monolayers

“…We demonstrate a record tunability up to 18 meVmuch larger than the best reported values in 2D materials 30 . Moreover, the SPEs retain a high-purity single photon emission upon the introduction of strain fields, as shown by time-correlation measurements 28 .…”

Modular system for fluorescence-based single photon generation using a retro-reflector

“…This feature is the same as those observed in earlier studies, 13 and the spec-tral shape indicates that this fluorescence center has the atomic formation similar to the defect found to be radiatively efficient. 14 Correlation dips, appeared at the zero time delay as in Fig.4B and C, are the prominent feature of single photons, meaning that single photons are not detected twice. Photon number statistics ideally have no coincidence of detection events in the HBT module and zero secondorder coherence (g (2) (0) = 0).…”

Origin of selective enhancement of sharp defect emission lines in monolayer WSe2 on rough metal substrate

“…A plethora of SPE systems have been studied to date such as trapped atoms and ions, colour centres in high band gap materials like diamond and nanostructures such as carbon nanotubes and quantum dots [5]. Signatures of SPEs have also been observed from highly localized spots close to the edges of the flakes of atomically thin layers of transition metal dichalcogenides (TMDs) [6][7][8][9][10][11][12] and also from other 2D materials such as graphene [13] and hexagonal Boron Nitride (hBN) [14][15][16][17][18]. The microscopic origin of these SPEs is yet to be thoroughly understood, but experimental results [8,10] and theoretical calculations [14,15,19,20] attribute their origin to the recombination of excitons bound to quantum dot like confinement potentials which arise from unique point defects in the crystal.…”