AI Insight
This study uses first-principles calculations to systematically characterize point defects in bulk hexagonal diamond (HD), a recently synthesized carbon allotrope with superior mechanical properties compared to cubic diamond. The research finds that carbon vacancies (VC) dominate intrinsic conductivity, while boron acts as an effective p-type dopant and nitrogen/phosphorus enable n-type conductivity. Additionally, specific defect complexes (VC, MgC, and XV) exhibit multiple spin and charge states within the HD band gap, identifying them as promising candidates for qubit hosting.
Why it matters
These findings provide a theoretical roadmap for engineering the electrical conductivity of hexagonal diamond and exploiting its defects as quantum bits (qubits), with potential applications in quantum computing, quantum sensing, and advanced industrial technologies.
arXiv:2604.22393v2 Announce Type: replace-cross
Abstract: Hexagonal diamond (HD), an exotic carbon allotrope recently synthesized in bulk form, exhibits superior mechanical properties compared to cubic diamond (CD) and holds promise for advanced industrial and quantum applications. Using first-principles calcu-lations, we systematically investigate intrinsic defects, extrinsic dopants, and defect complexes in HD. Our study shows that VC dominates intrinsic conductivity, while Ci is unstable. Among extrinsic dopants, boron acts as a benign acceptor enhancing p-type conductivity, whereas nitrogen and phosphorus serve as effective donors for n-type conductivity. Group II and Group IV dopants, however, introduce high formation energies or neutral charge states with limited impact. Furthermore, VC, MgC and XV defect com-plexes display multiple spin and charge states within the HD band gap, highlighting their potential as color centers for hosting qubits. These results not only clarify the defect physics of HD but also demonstrate its broader implications for conductivity engineering and quantum technologies.