HAWKING PROCESS IN SOLIDS - QUANTUM GENERATION OF PHONON BURSTS BY A STRONGLY EXCITED MODE

We examine quantum decay of localized vibrations in anharmonic crystal lattice. The theory which describes two-phonon anharmonic relaxation can be applied both to local modes associated with substitutional impu rity and to intrinsic local modes (ILM) in perfect lattices. It is fou nd that for sufficiently high initial excitations relaxation of vibrat ions is non-exponential, it demonstrates explosion-like behavior at sp ecific stages of evolution. The course of the relaxation is determined by the initial value of energy, temperature, direction of vibrations. As an example we present the results of calculations of the relaxatio n of an odd local (impurity) mode in a simple cubic lattice and discus s the influence of quantum fluctuations on the stability of the ILM in one-dimensional monatomic chain.