Comparative study of quantum emitter fabrication in wide bandgap materials using localized electron irradiation

TL;DR

This study compares the fabrication of quantum emitters in various wide bandgap materials using localized electron irradiation, highlighting its effectiveness in hBN but limitations in other crystals, and explores defect activation mechanisms.

Contribution

It demonstrates the selective effectiveness of electron irradiation in creating quantum emitters in hBN and investigates defect activation mechanisms across different materials.

Findings

High yield of single photon emitters in hBN using electron irradiation

Inability to produce emitters in mica, silicon carbide, and gallium nitride with the same method

Emitter formation in hBN may involve activating pre-existing defects through charge manipulation

Abstract

Quantum light sources are crucial foundational components for various quantum technology applications. With the rapid development of quantum technology, there has been a growing demand for materials with the capability of hosting quantum emitters. One such material platform uses fluorescent defects in hexagonal boron nitride (hBN) that can host deep sublevels within the bandgap. The localized electron irradiation has shown its effectiveness in generating deep sublevels to induce single emitters in hBN. The question is whether localized (electron beam) irradiation is a reliable tool for creating emitters in other wide bandgap materials and its uniqueness to hBN. Here, we investigate and compare the fabrication of quantum emitters in hBN and exfoliated muscovite mica flakes along with other 3D crystals, such as silicon carbide and gallium nitride, which are known to host quantum emitters. We used our primary fabrication technique of localized electron irradiation using a standard scanning electron microscope. To complement our experimental work, we employed density functional theory simulations to study the atomic structures of defects in mica. While our fabrication technique allows one to create hBN quantum emitters with a high yield and high single photon purity, it is unable to fabricate single emitters in the other solid-state crystals under investigation. This allows us to draw conclusions on the emitter fabrication mechanism in hBN, which could rely on activating pre-existing defects by charge state manipulation. Therefore, we provide an essential step toward the identification of hBN emitters and their formation process.