Nitrogen vacancy centers

Bermudez, A., Jelezko, F., Plenio, M.B. and Retzker, A. (2011) Electron-mediated nuclear-spin interactions between distant nitrogen-vacancy centers. Phys. Rev. Lett., 107, 150503. 

Demirplak and Rice developed the counter-diabatic control protocol while studying control methods that efficiently transfer population between a selected initial state and a selected target state of an isolated molecule [11-13]. The protocol has been studied for manipulation of atomic and molecular states [11, 12, 19] and spin chain systems [20, 21]. Experiments with the counter-diabatic protocol have been demonstrated for the control of BECs [22] and the electron spin of a single nitrogen-vacancy center in diamond [23]. The counter-diabatic field (CDF) protocol is identical with the transitionless driving protocol, independently proposed by Berry a few years later [24]. A discussion of the relationship between these approaches and several of the other proposed shortcuts to adiabaticity can be found in the review by Torrontegui and coworkers [10]. 

The so-called N-V-centers (nitrogen-vacancy centers) constitute very interesting defects of the diamond lattice. As described in Section 5.2.1, they consist of a nitrogen atom incorporated into the lattice and an adjacent vacancy. Fluorescence in the red to infrared range of the spectmm can be induced by excitation with... 

STED microscopy has important applications outside biology as well. For example, it currently is the only method to locally and noninvasively resolve the 3D assembly of packed nanosized colloidal particles [98,99]. In the realm of solid-state physics, STED microscopy has recently imaged densely packed fluorescent color centers in crystals, specifically charged nitrogen vacancy (NV) centers in diamonds [100]. NV centers in diamond have attracted attention, because of their potential application in quantum cryptography and... 

Fig. 19.4. Stimulated emission depletion (STED) microscopy reveals densely packed charged nitrogen vacancy (NV) color centers in a diamond crystal, (a) State diagram of NV centers in diamond (see inserted sketch) showing the triplet ground ( A) and fluorescent state ( E) along with a dark singlet state ( E) and the transitions of excitation (Exc), emission (Em), and stimulated emission (STED). (b) The steep decline in fluorescence with increasing intensity /sted shows that the STED-beam is able to switch off the centers almost in a digital-like fashion. This nearly rectangular ...

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]. 

Pressure treatment of p-BN polycrystals leads to a change both of broad-band parameters (A, B, C) and of the zero-phonon lines of the cathodoluminescence spectra and to a change in the appearance of RC centers. The centers PC-1 (2.84 eV), PC-2 (2.325 eV), and PC-3 (1.79 eV probably an interstitial center) have been detected in pressure-treated samples. The appearance of the A and B bands (between 1.85 and 3.25 eV) can be connected with electronic states in the band gap via boron and nitrogen vacancies, the appearance of the C band (1.55 to 1.85 eV) depends on the plastic deformation [29 to 31]. 

The color of diamond due to nitrogen impurities has been described in Section 9.6.3 It has been found that nitrogen impurities that are located next to a carbon vacancy in diamond thin films endow the solid with quite new properties, somewhat similar to the properties of a solid containing FLi centers compared with ordinary F centers. The diamond structure is built up of carbon atoms each surrounded by four... 

Figure 9.27 A (N-V) center in diamond, consisting of a carbon atom vacancy and a neighboring nitrogen atom impurity.

The H3 center is connected with a pair of nitrogen atoms, which captures one vacancy, while the H4 center is principally the same but with a slightly different configuration. Defect S2 is beheved to be due to a combination of two vacancies and one nitrogen atom, while S3 is connected with a combination of several nitrogen atoms and a vacancy and SI with a vacancy-nitrogen pair. 

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