The stabilization of width of multiple-quantum NMR spectrum induced by decoherence

TL;DR

This paper investigates how decoherence stabilizes the width of multiple-quantum NMR spectra over time, providing a new explanation for observed spectral behaviors and quantifying the dependence on perturbation strength.

Contribution

It offers an alternative explanation for spectral width stabilization in MQ NMR, emphasizing the role of different decay rates of spectral components due to decoherence.

Findings

Spectral width tends to a constant with increasing time.

Spectral width decreases as perturbation strength increases.

Calculated widths match experimental observations.

Abstract

As opposed to traditional methods of multiple-quantum NMR spectroscopy authors of the article [G.A. Alvarez, D. Suter, Phys. Rev. A 84, 012320 (2011)] generated the effective double-quantum Hamiltonian, with the slight adding usual secular dipole-dipole Hamiltonian to the first one at the stage of the correlations preparing (so the perturbation appeared). At this framework the width of MQ spectra reveals tending to any constant amount with the growing up of the time. Also there were shown that the spectral width decreases with increasing perturbation strength. The growing up of the cluster size as it was supposed by G.A. Alvarez and D. Suter was restricted by mentioned perturbation. We are assuming an alternative explanation. The growing up of cluster size still goes on but the width of MQ spectrum becomes stable because of different decay rate of MQ-spectral components in dependence on theirs location in spectrum. Here we are calculating the widths of MQ spectra in dependence on the time of "preparation" for different values of the perturbation strength and by this way we get the dependence of stabilized amount of MQ-spectrum width on mentioned strength. So, the excellent compliance obtains with the analogues experimental relation observed in Ref. [Phys. Rev. A 84, 012320 (2011)].