Anomalous properties of lattice TO vibrations in HgTe. II: One-dimensional model of a crystal with a two-well potential

Anomalous properties of the main lattice mode ω TO of HgTe, manifested by a strong increase in the damping parameter and in the frequency of the ω TO mode on increase in temperature, are explained by a one-dimensional model of a crystal with a two-well potential. The increase in the damping parameter of the ω TO mode with temperature is a consequence of the interaction of phonon-like plane waves with domain walls whose motion is accompanied by the transfer of electrons from one off-center well to another equivalent well