Diamond nitrogen-vacancy center

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]. 

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.

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. 

The N3 optical center is one of the best known in steady-state luminescence spectra diamond. It is connected with three substitutional nitrogen atoms botmded to a common carbon atom or a vacancy, the ground state being a level and the excited state where luminescence originates a state (C3V point group). The zero-phonon line occurs at 2.985 eV and absorption and emission spectra show very closely a mirror relationship (Bokii et al. 1986). The N3 prompt luminescence decay is exponential and equal to 40 ns. Time-resolved luminescence spectroscopy enables to detect that N3 center has some metastable levels between the emitting and ground state. One of the decay paths of these metastable levels is delayed N3 luminescence, which occurs... 

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