Defects in hexagonal boron nitride for quantum technologies

TL;DR

This paper surveys hexagonal boron nitride (hBN) as a 2D, wide-bandgap host for quantum defects that exhibit room-temperature optical and spin activity. It reviews progress in bright, high-purity single-photon emission for quantum communication and indistinguishable-photon generation for optical computing, and surveys spin-defect platforms in hBN with potential for quantum networking and sensing. The authors emphasize defect structure identification through ab initio calculations and advanced imaging, highlighting challenges in excited-state modeling, hyperfine fingerprints, and correlating atomic structures with optical signatures. They argue that hBN offers unique advantages for in-situ 2D sensing and nanoscale quantum sensing, and potentially for free-space/satellite QKD, while calling for coordinated theory–experiment efforts to realize scalable, defect-engineered devices.

Abstract

Atomic defects in solid-state materials are building blocks for future quantum technologies, such as quantum communication networks, computers, and sensors. Until recently, a handful of defects in a small selection of host materials have been possible candidates. Recent developments have revealed that hexagonal boron nitride, a wide-bandgap two-dimensional material, hosts single-photon-emitting atomic defects with access to optically addressable electronic and nuclear spins at room temperature. Now, atomically thin quantum devices that operate at ambient conditions are a possibility. In this perspective, we discuss the recent progress, and challenges, in understanding the fundamental photophysics of defects in hBN, as well as specific opportunities they present for the development of quantum technologies.

Figures (4)

• Figure 1:
• Figure 2:
• Figure 3:
• Figure 4: