Multiphonon anharmonic decay of a quantum mode

Institute of Theoretical Physics, University of Tartu - Tähe 4, 51014 Tartu, Estonia Institute of Physics, University of Tartu - Riia 142, 51014 Tartu, Estonia

Received: 21 September 1998
Accepted: 14 December 1998

Abstract

A nonperturbative theory of multiphonon anharmonic transitions between energy levels of a local mode is presented. It is shown that the rate of transitions rearranges near the critical level number n_cr: at smaller n the process slows down, while at larger n it accelerates in time, causing a jump-like loss of energy followed by the generation of phonon bursts. Depending on parameters, phonons are emitted in pairs, triplets etc.