Journal of Chemical Physics
Spectral diffusion decay is calculated for a glass modeled by two level systems which are strongly coupled to phonons. The spin-phonon interaction induces an effective spin-spin interaction which dominates the energy scale. We show that spectral diffusion is a property of macroscopic local fields which fluctuate on time scales that are much longer than the spin-phonon relaxation time T1. We assume for the spectral diffusion a Gaussian distribution and derive a self-consistent equation for its variance which is nonlocal in time. At high temperatures, the variance grows linearly with time while at low temperatures, we find strong deviations from simple diffusive decay. In a particular case, the growth of the variance is steplike. For very long times, we find an asymptotic sublinear behavior w∝t2/3. A heuristic argument shows that this law is determined by the form of the distribution.
Zürcher, Ulrich and Silbey, R., "Dephasing Processes in Glasses with Strong Strain Interactions" (1992). Physics Faculty Publications. 272.
© 1992 American Institute of Physics.