Optically detected magnetic resonance of a single Nitrogen-Vacancy electronic spin in diamond nanocrystals

Controlled and coherent manipulation of individual quantum systems is a fundamental key for the development of quantum information processing [1]. The Nitrogen-Vacancy (NV) color center in diamond has been identified as a unique system offering individual electron spin control and very long phase memory time, even at room temperature [2]. The spin state, which can be coherently manipulated with microwave pulses, can be optically readout by a drop of photoluminescence when the applied microwave frequency is equal to the resonant frequency of the system [2]. In order to apply for, for example, spin-resonance-based magnetometry [3], an understanding and a control of electron spin resonance (ESR) of a single NV center in a diamond nanocrystal (nanodiamond) is neccessary.