Nitrogen vacancy

The main hardware types offered by physics are mentioned, namely trapped ions (or trapped atoms), quantum dots, quantum optical cavities, rf superconducting quantum interference devices (SQUIDs) and nitrogen-vacancy (NV) defects on diamond. Some are important simply as a benchmark to evaluate the quality of the implementations offered by chemistry, whereas others might be combined with lanthanide complexes to produce heterogeneous quantum information processors which combine the advantages of different hardware types. 

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]. 

NMR NN NOM NP NR NTA NTS NV NVOC NVP nuclear magnetic resonance next-neighbor (interactions) nano-on-micro nanoparticle nanorod nitrilotriacetic acid nonadecenyltrichlorosilane nitrogen vacancy (defect sites) nitroveratryloxycarbonyl naphthalenylvinylpyridine... 

Rutz [13] reported a broad near-UV band in the electroluminescence spectra, extending from 215 nm into the blue aid of the visible range. Moiita et al [14] observed the cathodoluminescence with peaks or humps in epitaxial AIN films on (0001) sapphire substrates at about 2.71, 2.88, 3.12, 3.19, 3.33 and 3.53 eV. They insisted that the last two peaks were due to nitrogen vacancies or interstitial Al impurities, and that the first two peaks were attributed to oxygen impurities or defects induced by the increase in oxygen concentration. 

In general, low electron concentration and high mobility appear to depend most critically on reduction in nitrogen vacancies and a morphology in which polycrystallinity is not disadvantageous, provided crystallite interfaces are intimate and sizes are significantly larger than the mean free path determined by other scatterers. 

The doping can be affected by native defects such as vacancies (Vo and VN), self-interstitials (Gai and Nj) and antisites (GaN and Ng,). Such defects may cause self-compensation, e.g. when one tries to dope the material p-type, certain native defects which act as donors may spontaneously form and compensate the deliberately introduced acceptors. In GaN, a specific native defect was long believed to play an even more important role the nitrogen vacancy, which acts as a donor, was thought to occur in large concentrations, thereby causing unintentional n-type conductivity. 

FIGURE 2 Formation energy as a function of Fermi energy for Mg in different configurations (Ga-substitutional, N-substitutional and interstitial configuration). Also included are the native defects (nitrogen vacancies) and interstitial H. 

Specific results for donor and acceptor doping have been reviewed. The main conclusions for n-fype GaN are that (i) nitrogen vacancies are not responsible for unintentional n-type conductivity ... 

Native defects have sometimes been invoked not just as sources of compensation, but as sources of doping. The nitrogen vacancy in GaN is a prime example for a long time the nitrogen vacancy was thought to be the source of n-type conductivity in GaN. As early as 1983 it was pointed out that unintentional incorporation of oxygen was a more likely explanation [1], Still, it is only recently that unintentional impurities have become widely accepted as the source of n-type conductivity, thanks in part to contributions from first-principles theory (see Datareview A8.1). In this Datareview we will describe some of those theoretical results, for vacancies as well as other native defects (self-interstitials and antisites). Experimental information about native defects in the nitrides is very scarce at this time we will include references where available. 

FIGURE 3 Formation energy as a function of Fermi level for Mg, nitrogen vacancies, interstitial H and hydrogen-vacancy complexes in GaN [1,14],... 

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... 

---