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Diamond Materials

Diamond Materials for Quantum Application

23. September 2014: The DFG research group FOR 1493 “Diamond Materials and Quantum Applications” goes into its second funding period. FOR1493 is a national research consortium funded by the Deutsche Forsch-ungsgemeinschaft.

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ERC Advanced Grant

ERC

Tailoring spin defects in diamond by lattice charging

Atomic-size spin defects in solids are unique quantum systems. Most applications require nanometer positioning accuracy, which is typically achieved by low-energy ion implantation. A drawback of this technique is the significant residual lattice damage, which degrades the performance of spins in quantum applications. Here we show that the charge state of implantation-induced defects drastically influences the formation of lattice damage during implantation and thermal annealing. Charging of vacancies at, for example, nitrogen implantation sites suppresses the formation of vacancy complexes, resulting in tenfold-improved spin coherence times and twofold-improved formation yield of nitrogen-vacancy centers in diamond. This is achieved by confining implantation defects into the space-charge layer of free carriers (holes) generated within a p + -i junction structures with overgrown layer of diamond with high concentration of boron acceptors. Combined with numerical calculations, these results bring new insights into the dynamic mechanisms of self-diffusion and defect formation at single implantation sites. In the future, the concept of defect charging could be implemented into various solid-state systems for improved engineering of quantum devices.

References:
F. F. de Oliveira, et al. Nat. Commun. 8, 15409 doi: 10.1038/ncomms15409 (2017)