Anharmonic Decay of Vibrational States in Amorphous Silicon

TL;DR

This paper calculates anharmonic decay rates of vibrational states in amorphous silicon, revealing rapid decay on picosecond timescales and highlighting differences from experimental observations.

Contribution

It provides the first detailed theoretical calculation of vibrational decay rates in amorphous silicon using a realistic atomic model.

Findings

Vibrational states decay on picosecond timescales.

Decay follows the two-mode density of states, similar to crystalline silicon.

Localized states show little change in decay rates.

Abstract

Anharmonic decay rates are calculated for a realistic atomic model of amorphous silicon. The results show that the vibrational states decay on picosecond timescales and follow the two-mode density of states, similar to crystalline silicon, but somewhat faster. Surprisingly little change occurs for localized states. These results disagree with a recent experiment.