Scalable nanoscale positioning of highly coherent color centers in prefabricated diamond nanostructures.

Kim, Sunghoon; London, Paz; Yang, Daipeng; Hughes, Lillian B; Ahlers, Jeffrey; Meynell, Simon; Mitchell, William J; Mukherjee, Kunal et al. · Nat Commun · 2025

basic_science · Level V

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Abstract

Nanophotonic devices in color center-containing hosts provide efficient readout, control, and entanglement of the embedded emitters. Yet control over color center formation - in number, position, and coherence - in nanophotonic devices remains a challenge to scalability. Here, we report a controlled creation of highly coherent diamond nitrogen-vacancy (NV) centers with nanoscale three-dimensional localization in prefabricated nanostructures with high yield. Combining nitrogen δ-doping during chemical vapor deposition diamond growth and localized electron irradiation, we form shallow NVs registered to the center of diamond nanopillars with wide tunability over NV number. We report a positioning precision of  ~ 4 nm in depth and 46(1) nm laterally in 280 nm-diameter pillars (102(2) nm in bulk diamond). We reliably form single NV centers with long spin coherence times (average <math xmlns="http://www.w3.org/1998/Math/MathML"> <msubsup><mrow><mi>T</mi></mrow> <mrow><mn>2</mn></mrow> <mrow><mi>H</mi> <mi>a</mi> <mi>h</mi> <mi>n</mi></mrow> </msubsup> <mo>=</mo> <mn>98</mn> <mspace></mspace> <mi>μ</mi> <mi>s</mi></math> ) and higher average photoluminescence compared to NV centers randomly positioned in pillars. Our method can improve the performance of various NV-based devices. In the realm of magnetic sensing, we achieve a 3 × improved yield of NV centers with single electron-spin sensitivity over conventional implantation-based methods. Our high-yield defect creation method will enable scalable production of solid-state defect sensors and processors.