Quantum detect jumps

Figure 4 Simulated 14N (43.34 MHz) rotor-synchronized MAS spectra corresponding to a two-site jump process and detection of either singlequantum (columns Al, Bl, Cl) or double-quantum coherence (columns A2, B2, C2). The spectra in columns A (A1.A2) are calculated using parameter set P6, whereas parameter sets P7 and P8 are used for columns B (Bl, B2) and C (Cl, C2), respectively. Gaussian line broadenings of 75 (Al, Bl, Cl), 50 (A2, B2) or 100 (C2) Hz were applied prior to Fourier transformation. The logarithm of the rate constant k is indicated at each row of spectra.

Figure 5 Maximum intensity as a function of log(fc) for simulated 14N (43.34 MHz) MAS spectra of a two-site jump process detecting either (A) single-quantum coherence or (B) double-quantum coherence. In both plots, the solid line corresponds to parameter set P6, the solid triangles to parameter set P7 and the solid squares to parameter set P8.

After more than one 100 years of unquestionable successes [128], there is a general agreement that quantum mechanics affords a reliable description of the physical world. The phenomenon of quantum jumps, which can be experimentally detected, should force the physicists to extend this theory so as to turn the wave-function collapse assumption, made by the founding fathers of quantum mechanics, into a dynamical process, probably corresponding to an extremely weak random fluctuation. This dynamical process can be neglected in the absence of the enhancement effects, triggered either by the deliberate measurement act or by the fluctuation-dissipation phenomena such as Brownian motion. This enhancement process must remain within the limits of ordinary statistical physics. In this limiting case, the new theory must become identical to quantum mechanics. 

Ion tr experiments can achieve high detection efficiency of the ion s internal states. Unit detection efficiency has been achieved in previous experiments on quantum jumps [13] where the internal state of the ion is indicated by light... 

Figure 12. Fluorescence counts detected for a single terrylene molecule in p-terphenyl (site Xi) as a function of time. The quantum jumps are clearly visible as discrete intenuptions of the fluorescence. The sample was cooled to 1.4 K and the molecule was excited with an (free space) intensity of 62.5 W/cm. (b), a I s section of a 26.8 s data set, (a), a region covering 80 ms displayed on a magnified scale.

Variable-temperature NMR experiments provide information about the dynamic processes that occur in solids. It is well known that, for a semicrystalline polymer such as polyethylene (PE), a higher rate of cooling from the melt leads to lower crystallinity C CP/MAS NMR establishes that the cooling rate also affects the structure and motion of the amorphous domain [217]. Many of the dynamic properties of PE, such as jump rates and activation energy, can be explained in terms of chain diffusion between the phases, as detected by 2-D exchange C NMR [218]. Very slow motions in the crystalline a-form of deuterated poly(vinylidene fluoride) have also been detected by exchange NMR [219]. Double-quantum transitions can occur in materials in which spin pairs are only a few bonds apart this... 

Fig. 6.8 The quantum jump technique to perform state measurements. The levels jp) and j/) are coupled by a laser. Level 1/) decays only to ]p). If and only if the ion is in p) it will exhibit fluorescence which can be detected.

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