Experimental and Computational Investigations of Boron-Nitrogen Pairs in Diamond for Quantum Information Applications

Donor-acceptor pairs (DAP) in semiconductors that exhibit large electric dipole moments in their ground and excited states are promising candidates that could enable new functionalities in solid state quantum information science. We investigate substitutional Boron and Nitrogen defects and how they form DAP in diamond using density functional theory (DFT). Zero phonon lines (ZPL) of each DAP shell with increasing interdefect distance is computed and the Coulombic nature of the electron-hole interaction that dominates the emission spectrum is captured. We use formation energy diagrams to understand the charge state transitions in the system. We compute the differences in polarization between ground and excited states using maximally localized Wannier functions, which show unusually large electric dipole moments. We explore the effect of an external electric field to make use of these large dipole moments to tune ZPL energies in a broad range. We explicitly calculate a correction term for DAP that have overlapping Bohr radii. We complement our computational results with photoluminescence experiments on diamond samples implanted with Boron and Nitrogen. Our results indicate that Boron and Nitrogen in diamond are suitable candidates for such DAP that show a broad range of tunability.