Room-Temperature High-Purity Single Photon Emission from Carbon-Doped Boron Nitride Thin Films

TL;DR

This paper reports the development of high-purity, stable single photon emitters in carbon-doped hexagonal boron nitride thin films grown by pulsed laser deposition, operating at room temperature with exceptional brightness and stability.

Contribution

It introduces a scalable method for producing high-quality single photon emitters in hBN using low-temperature PLD with in-situ doping, achieving record low g(2)(0) values.

Findings

Achieved g(2)(0) of 0.015, among the lowest for room temperature SPEs.

Demonstrated high brightness of around 0.5 million counts/sec.

Maintained stability over 15 minutes of continuous operation.

Abstract

Hexagonal boron nitride (hBN) has emerged as an excellent host material for generating room temperature single photons exhibiting high brightness and spin-photon entanglement. However, challenges in improving purity, stability, and scalability limit its use in quantum technologies. Here, we demonstrate highly pure and stable single photon emitters (SPEs) in hBN by directly growing carbon-doped, centimeter-scale hBN thin films using the pulsed laser deposition (PLD) method. These SPEs exhibit room temperature operation with polarized emission, achieving a g(2)(0) value of 0.015, which is among the lowest reported for room temperature SPEs and the lowest achieved for hBN SPEs. It also exhibits high brightness ( around 0.5 million counts per second), remarkable stability during continuous operation (> 15 minutes), and a Debye-Waller factor of 45%. First-principles calculations reveal unique carbon defects responsible for these properties, enabled by PLD's low-temperature synthesis and in-situ doping. Our results demonstrate an effective method for large-scale production of high-purity, stable SPEs in hBN, enabling robust quantum optical sources for various applications.