Nitrogen-vacancy centres

A. T. Collins, M. Kamo, and Y. Sato, Optical centres related to nitrogen, vacancies and interstitials in polycrystalline diamond films grown by plasma-assisted chemical vapour deposition, J. Phys. D Appl. Phys., 22(9) 1402-1405 (1989)... 

Precise characterization and understanding of quantum properties of single colour centers in diamond is still under progress. A great variety of the colour centers and the complex environment conditions together with the strict limitations posed on the candidates for QIT applications makes the characterization an important and hard problem. The mostly investigated potential candidate is the nitrogen vacancy [N-V]" defect centre in diamond [8]. 

Figure 7.5 (a) Artificial quantum dot architecture showing the confined electron spins, (b) A diamond unit cell showing a NV centre - a nitrogen defect and a carbon vacancy - with an S = 1 electronic spin... 

From the ionic conductivity data it is concluded that uranium is incorporated as (UOg) in crystals that have been grown in air, since according to the incorporation reactions this is the only centre that is concordant with an increase in fluoride-ion conductivity upon increasing uranium content. In crystals that have been grown in nitrogen, uranium will be incorporated as (UO4F2) , since in this way sodium-ion vacancies are formed. 

H = anion vacancy, O cation vacancy, (Nj) = exciton, E = phonon, fe j = F-centre. The F-centre later decomposes to form nitrogen gas, R-centre etc. 

A single NE8 center in diamond is shown in Fig. 1. It consists of a Ni atom in the position of semi-vacancy (the centre of divacancy) of two nearest carbon sites according to their positions in the diamond lattice and four nearest nitrogen atoms in the substituting positions [5]. The cluster C33H24N4Ni+1 was generated in the spin-doublet (S=l/2) ground state. 

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