WW Kolloquium: Christoph Findler “NV color centers in isotopically-controlled CVD-diamond for quantum technologies”

Christoph Findler
CTO, Diatope GmbH
“NV color centers in isotopically-controlled CVD-diamond for quantum technologies”

Diamond has always been fascinating for humanity, either as gemstones with brilliant colors or as one of the most durable materials for mechanical tools and coatings. During the last decades, both the color in form of impurities and the hardness of diamond turned out to be attractive also for quantum technologies. Until today a multitude of optically active diamond defects has been found and many of them have been identified in terms of structure and composition. The impurities with optical absorption in the visible wavelength spectrum can color diamond and are therefore called color centers.
The most studied color center in diamond is the negatively charged nitrogen vacancy center (NV). Consisting of a carbon vacancy and an adjacent substitutional nitrogen impurity, it is an atomic defect. The NV center is paramagnetic and carries in its negative charge state a S = 1 electron spin with coherence times up to milliseconds even at room temperature.
The high stability at ambient conditions makes bulky equipment like cryostats or vacuum pumps unnecessary and enables therefore real-world quantum applications outside the laboratory. As a consequence, NV centers in synthetic single-crystalline diamond are a promising and emerging platform for quantum sensing technologies. The realization of such solid-state based quantum sensors is widely studied and requires reproducible manufacturing of NV centers with controlled spin properties, including the spin bath environment within the diamond crystal.
Here, together with an introduction to NV quantum sensing the key parameters of NV diamonds are discussed to achieve magnetic field sensitivities down to the picotesla range. The resulting material requirements are then translated into the necessary fabrication steps involving plasma-assisted chemical vapor deposition of isotopically purified diamond and the generation of color centers. Finally, the talk ends with an outlook to room-temperature quantum computing with diamond.

Zoom:
meeting-ID: 648 8554 2073 or
zoom code: 173088