Identification of an Oxygen Defect in Hexagonal Boron Nitride

Area of Science:

• Quantum Information Science
• Materials Science
• Condensed Matter Physics

Background:

• Paramagnetic fluorescent defects in 2D hexagonal boron nitride (hBN) are crucial for quantum information processing.
• Accurate identification of these defects is challenging due to the dense nuclear spin environment.

Purpose of the Study:

• To identify elusive paramagnetic fluorescent defects in hBN.
• To establish electron paramagnetic resonance (EPR) spectroscopy combined with first-principles calculations as a reliable defect identification method.

Main Methods:

• Experimental electron paramagnetic resonance (EPR) spectroscopy.
• First-principles simulations using hybrid density functional theory.
• Many-body perturbation theory for accurate spectral calculations.

Main Results:

• A specific EPR center was identified as the negatively charged oxygen vacancy complex.
• Calculations accurately reproduced experimental photoluminescence spectra for this defect.
• The negatively charged oxygen vacancy complex exhibits coherent emission around 2 eV.

Conclusions:

• The combination of experimental EPR and first-principles modeling is essential for defect identification in hBN.
• The negatively charged oxygen vacancy complex is a promising candidate for quantum applications.
• This work advances the understanding and utilization of defects in hBN for quantum technologies.