FAR INFRARED THERMAL RADIATIVE PROPERTIES OF POLAR MATERIALS FROM FIRST-PRINCIPLE SIMULATIONS

摘要

The Lorentz oscillator model is well-known for its effectiveness to describe the far infrared optical properties of ionic materials. The parameters including oscillator strength and damping factor in the model are usually obtained by fitting to experimental results. In this paper, a new method, based on static and dynamic first-principle simulations, is developed to parameterize the Lorentz oscillator model with the initial atomic structure as the only input parameter. This method is then applied to predict the far infrared reflectance of GaAs, which shows excellent agreement with experimental measurements.