High-order vibrational relaxation: a nonperturbative theory
Institute of Physics, University of Tartu, Riia 142, 51014 Tartu, Estonia
Corresponding author: a firstname.lastname@example.org
Published online: 31 July 2002
A nonperturbative theory of the multiphonon relaxation of a localized vibrational mode, caused by a high-order anharmonic interaction with the nearest atoms of the crystal lattice, is proposed. It relates the rate of the process to the positive frequency part of the time-dependent non-stationary displacement correlation function of atoms. The nonlinear integral equation for this function is derived and solved numerically. We have found that the rate exhibits a critical behavior: it sharply increases near a specific (critical) value(s) of the interaction; the corresponding dependence is characterized by the critical index , where k is the number of the created phonons.
PACS: 63.50.+x – Vibrational states in disordered systems / 71.23.An – Theories and models; localized states
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002