Efficient single photon emission from a high-purity hexagonal boron nitride crystal

TL;DR

This paper demonstrates highly photostable single photon emission from a high-purity hexagonal boron nitride crystal, highlighting its potential for quantum information and metrology applications.

Contribution

It provides a detailed analysis of defect-related single photon emission in high-purity hBN, showing high brightness and quantum efficiency under ambient conditions.

Findings

Identification of individual defects emitting stable single photons

High quantum efficiency of radiative transitions in hBN defects

Potential for applications in quantum information science and metrology

Abstract

Among a variety of layered materials used as building blocks in van der Waals heterostructures, hexagonal boron nitride (hBN) appears as an ideal platform for hosting optically-active defects owing to its large bandgap ($\sim 6$ eV). Here we study the optical response of a high-purity hBN crystal under green laser illumination. By means of photon correlation measurements, we identify individual defects emitting a highly photostable fluorescence under ambient conditions. A detailed analysis of the photophysical properties reveals a high quantum efficiency of the radiative transition, leading to a single photon source with very high brightness. These results illustrate how the wide range of applications offered by hBN could be further extended to photonic-based quantum information science and metrology.