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arXiv · 2608.02350

Revealing and reducing growth-induced interfacial disorder in preferentially aligned nitrogen-vacancy centers in diamond

Cheng-I Ho·Marina Davydova·Patrik Straňák·Felix Hoffmann·Peter Knittel·Andrej Denisenko·Jörg Wrachtrup
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Abstract

Nitrogen-vacancy (NV) centers in chemical-vapor-deposition (CVD) diamond can form preferentially oriented ensembles with high sensing performance and low densities of lattice defects. Thin films of this material are a cornerstone of various imaging modalities. However, nitrogen injection needed to produce such films can transiently drive growth out of equilibrium, generating interfacial strain and spin defects that degrade NV coherence. Here, we investigate this disorder in $^{12}\text{C}$-enriched, preferentially oriented NV layers grown on (111) diamond using two nitrogen-injection procedures, combined with nanometer-scale selective plasma etching and NV spin-coherence measurements. Pulsed nitrogen injection produces a pronounced nitrogen overshoot within a 60--80 nm interfacial region, generating excessive amounts of defects. By contrast, smooth nitrogen delivery through mass flow controllers substantially suppresses interfacial disorder, yielding coherence properties close to the theoretical limit imposed by spin-bath noise. A 50-nm NV layer is used to demonstrate proton nuclear magnetic resonance detection. This work reveals the role of interfacial disorder associated with the nitrogen-doping procedure and provides a route to growing high-quality, thin NV-doped layers for quantum-sensing applications.

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Cheng-I Ho, Marina Davydova, Patrik Straňák, Felix Hoffmann, Peter Knittel, Andrej Denisenko, Jörg Wrachtrup. 2026-08-03. Revealing and reducing growth-induced interfacial disorder in preferentially aligned nitrogen-vacancy centers in diamond. https://arxiv.org/abs/2608.02350

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