Probing the Optical Dynamics of Quantum Emitters in Hexagonal Boron Nitride

TL;DR

This study investigates the optical dynamics of quantum emitters in hexagonal boron nitride, revealing complex electronic states and transitions through spectroscopy and modeling, advancing understanding of their quantum properties at room temperature.

Contribution

It provides the first detailed experimental analysis of the electronic structure and optical dynamics of quantum emitters in hexagonal boron nitride, supported by simulations and theoretical models.

Findings

Quantum emitters exhibit ideal single-photon emission with antibunching.

Photoluminescence lineshapes indicate vibronic transitions.

Complex optical dynamics involve multiple electronic excited states.

Abstract

Hexagonal boron nitride is a van der Waals material that hosts visible-wavelength quantum emitters at room temperature. However, experimental identification of the quantum emitters' electronic structure is lacking, and key details of their charge and spin properties remain unknown. Here, we probe the optical dynamics of quantum emitters in hexagonal boron nitride using photon emission correlation spectroscopy. Several quantum emitters exhibit ideal single-photon emission with noise-limited photon antibunching, $g^{(2)}(0)=0$. The photoluminescence emission lineshapes are consistent with individual vibronic transitions. However, polarization-resolved excitation and emission suggests the role of multiple optical transitions, and photon emission correlation spectroscopy reveals complicated optical dynamics associated with excitation and relaxation through multiple electronic excited states. We compare the experimental results to quantitative optical dynamics simulations, develop electronic structure models that are consistent with the observations, and discuss the results in the context of ab initio theoretical calculations.