Localization and relaxation effects of weakly interacting anharmonic oscillators studied by infrared absorption spectroscopy

摘要

The vibrational dynamics of a two-phonon bound state has been examined by infrared absorption spectroscopy. This mode displays a spatial localization which is realized by a spectral separation from the continuum of two-phonon states by an energy gap of about 20 cm(-1). At elevated temperatures a phonon-assisted thermally activated decay of this localized state into the two-phonon continuum could be indentified. It is suggested that an inelastic scattering event by a substrate phonon is responsible for the decay. (C) 1998 Elsevier Science B.V. [References: 21]