Generation of narrowband quantum emitters in hBN with optically addressable spins

TL;DR

This paper demonstrates a simple thermal process to create high-density, narrowband quantum emitters in hBN with optically addressable spins at room temperature, significantly advancing quantum technology applications.

Contribution

It introduces a thermal processing method to generate spin-active quantum emitters in hBN with high density and room-temperature spin readout capabilities.

Findings

Over 25% of emitters show optical spin readout at room temperature

Generated spin defects exhibit S=1 and S=1/2 transitions

Method surpasses previous results in emitter density and spin addressability

Abstract

Electron spins coupled with optical transitions in solids stand out as a promising platform for developing spin-based quantum technologies. Recently, hexagonal boron nitride (hBN) - a layered Van der Waals (vdW) crystal, has emerged as a promising host for optically addressable spin systems. However, to date, on-demand generation of isolated single photon emitters with pre-determined spin transitions has remained elusive. Here, we report on a single step, thermal processing of hBN flakes that produces high density, narrowband, quantum emitters with optically active spin transitions. Remarkably, over 25% of the emitters exhibit a clear signature of an optical spin readout at room temperature, surpassing all previously reported results by an order of magnitude. The generated spin defect complexes exhibit both S = 1 and S = 1/2 transitions, which are explained by charge transfer from strongly to weakly coupled spin pairs. Our work advances the understanding of spin complexes in hBN and paves the way for single spin - photon interfaces in layered vdW materials with applications in quantum sensing and information processing.