Researchers at the University at Buffalo have predicted the optical fingerprints of atomic defects in hexagonal boron nitride, a material featuring a honeycomb-like pattern of boron and nitrogen atoms.
The atomic defects embedded within materials like hexagonal boron nitride are essential for future quantum technologies, yet they remain exceptionally difficult to spot. These microscopic flaws alter how a material responds to light, creating a distinctive optical signature that instruments can measure. The primary hurdle for scientists is determining which specific light responses correspond to which atomic structures.
To solve this, a research team led by the University at Buffalo developed computer models to simulate how different defects influence the intensity and polarization of light generated when the material is struck by a laser. Published on Oct. 19 in the American Chemical Society’s Nano Letters, the computer calculations aim to help researchers distinguish between various flaws and identify those best suited for emerging quantum applications.
Not all atomic defects are created equal. Making it easier to identify defects brings us another step closer to determining which ones have the properties we’re looking for,
Vasili Perebeinos, professor in the Department of Electrical and Computer Engineering in the UB School of Engineering and Applied Sciences
The team modeled 10 distinct atomic defects across the material. These included missing boron atoms, missing nitrogen atoms, and substitutions where carbon atoms replaced the original lattice elements. Certain defects were shown to significantly boost light production at double or triple the frequency of the incoming laser, depending on the light’s polarization.
Even defects composed of the same elemental atoms produced divergent light responses based purely on their spatial arrangement. When the team modeled two different configurations containing four carbon atoms, one configuration generated a strong light signal across two polarization directions, while the other produced a strong signal in only a single direction.
These distinctive light responses could eventually allow us to experimentally identify not only which atoms are involved in a defect, but also precisely how they’re arranged,
Paras N. Prasad, SUNY Distinguished Professor, Samuel P. Capen Chair in the Department of Chemistry, and executive director of UB’s Institute for Lasers, Photonics, and Biophotonics
Certain defects within hexagonal boron nitride can emit single photons released one at a time. These particles can carry quantum information for sensing and communication systems. The new computational work provides a roadmap for engineers looking to harness these single-photon emitters.
Instead of relying on individual sources of quantum light, we want to create entire arrays of them that could be used in future quantum technologies. That’s the main motivation for studying defects in these materials,
Vasili Perebeinos, professor in the Department of Electrical and Computer Engineering in the UB School of Engineering and Applied Sciences
The research received support from the U.S. Air Force Office of Scientific Research through a Multidisciplinary University Research Initiative award. The work was supported by the U.S. Air Force Office of Scientific Research as part of the Multidisciplinary University Research Initiative (MURI).
