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


Nanoengineered Diamond Waveguide

Nanoengineered Diamond Waveguide as a Robust Bright Platform for Nanomagnetometry Using Shallow Nitrogen Vacancy Centers

Photonic structures in diamond are key to most of its application in quantum technology. Here, we demonstrate tapered nanowaveguides structured directly onto the diamond substrate hosting shallow-implanted nitrogen vacancy (NV) centers. By optimization based on simulations and precise experimental control of the geometry of these pillar-shaped anowaveguides, we achieve a net photon flux up to ~ 1.7 × 10 6 s -1. This presents the brightest monolithic bulk diamond structure based on single NV centers so far. We observe no impact on excited state lifetime and electronic spin dephasing time (T 2) due to the nanofabrication process. Possessing such high brightness with low background in addition to preserved spin quality, this geometry can improve the current nanomagnetometry sensitivity ~ 5 times. In addition, it facilitates a wide range of diamond defects-based magnetometry applications. As a demonstration, we measure the temperature dependency of T 1 relaxation time of a single shallow NV center electronic spin. We observe the two-phonon Raman process to be negligible in comparison to the dominant two-phonon Orbach process.

Figure 2. A SEM image of an array of tapered nanopillars (scale bar = 3 µm). B SEM image of a diamond tapered nanopillar; height ~ 1.2 µm, top diameter ~ 400 nm, and bottom diameter ~ 900 nm (scale bar = 500 nm). C Confocal image of the tapered nanopillars (2.5 keV energy of implantation) under ambient conditions (scale bar = 5 µm).

Reference: | NanoLett. 2015, 15, 165-169
Author(s): S. Ali Momenzadeh, Rainer J. Stöhr, Felipe Favaro de Oliveira, Andreas Brunner, Andrej Denisenko, Sen Yang, Friedemann Reinhard, and Jörg Wrachtrup