Classical Lorentz harmonic oscillator model of photo-phonon inteaction

[hjaohuang]

Why the reciprocal of the damping rate in this model equal to the phonon lifetime? Can somebody give me a detailed exaplanation.

Thanks.

 

[chrisbaird]

The answer is dephasing. If there were no damping, an oscillator would go on forever. The damping rate is a characteristic rate at which the oscillation gets interrupted. In the quantum world, quantum states slowly dephase and have a lifetime describing this loss of coherence. With loss of coherence comes the destruction of the interaction, e.g. the oscillator stops oscillating.