Coherence properties of electron beam activated emitters in hexagonal boron nitride under resonant excitation

TL;DR

This study characterizes quantum emitters in hexagonal boron nitride, revealing narrow emission lines, coherent control via Rabi oscillations, and potential for scalable quantum technology applications.

Contribution

It provides detailed spectroscopic and coherence properties of position-controlled quantum emitters in hBN under resonant excitation, advancing their use in quantum technologies.

Findings

Narrow zero phonon line at ~436 nm with strong polarization

Spectral diffusion and phonon broadening contribute to 1-2 GHz linewidths

Rabi oscillations observed with coherence up to 0.90 ns

Abstract

Two dimensional materials are becoming increasingly popular as a platform for studies of quantum phenomena and for the production of prototype quantum technologies. Quantum emitters in 2D materials can host two level systems that can act as qubits for quantum information processing. Here, we characterize the behavior of position-controlled quantum emitters in hexagonal boron nitride at cryogenic temperatures. Over two dozen sites, we observe an ultra-narrow distribution of the zero phonon line at ~436 nm, together with strong linearly polarized emission. We employ resonant excitation to characterize the emission lineshape and find spectral diffusion and phonon broadening contribute to linewidths in the range 1-2 GHz. Rabi oscillations are observed at a range of resonant excitation powers, and under 1 ${\mu}$W excitation a coherent superposition is maintained up to 0.90 ns. Our results are promising for future employment of quantum emitters in hBN for scalable quantum technologies.