Perfectly aligned shallow ensemble nitrogen-vacancy centers in (111) diamond

• Published in: Applied physics letters 2017-07, Vol.111 (4)
• Main Authors: Ishiwata, Hitoshi, Nakajima, Makoto, Tahara, Kosuke, Ozawa, Hayato, Iwasaki, Takayuki, Hatano, Mutsuko
• Format: Article
• Language: English
• Subjects: Alignment; Applied physics; Chemical vapor deposition; Diamonds; Magnetic measurement; Nitrogen; NMR; Nuclear magnetic resonance; Nuclear spin; Organic chemistry; Substrates; Vacancies
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4993160

We report the formation of perfectly aligned, high-density, shallow nitrogen vacancy (NV) centers on the (111) surface of a diamond. The study involved step-flow growth with a high flux of nitrogen during chemical vapor deposition (CVD) growth, which resulted in the formation of a highly concentrated (>1019 cm−3) nitrogen layer approximately 10 nm away from the substrate surface. Photon counts obtained from the NV centers indicated the presence of 6.1 × 1015–3.1 × 1016 cm−3 NV centers, which suggested the formation of an ensemble of NV centers. The optically detected magnetic resonance (ODMR) spectrum confirmed perfect alignment (more than 99%) for all the samples fabricated by step-flow growth via CVD. Perfectly aligned shallow ensemble NV centers indicated a high Rabi contrast of approximately 30% which is comparable to the values reported for a single NV center. Nanoscale nuclear magnetic resonance demonstrated surface-sensitive nuclear spin detection and provided a confirmation of the NV centers' depth. Single NV center approximation indicated that the depth of the NV centers was approximately 9–10.7 nm from the surface with error of less than ±0.8 nm. Thus, a route for material control of shallow NV centers has been developed by step-flow growth using a CVD system. Our finding pioneers on the atomic level control of NV center alignment for large area quantum magnetometry.