Simulating Light Absorption and Emission in Materials

Abstract

In this paper, the author builds a simple model for light absorption and emission in materials, with a special focus on graphene. This is mainly due to its extraordinary optical properties near the Dirac points, as well as the band gap opening due to external electric field perturbations. A fully quantum mechanical treatment of light as well as the matter electrons is used. The theoretical model is based upon quantum optics, quantum dynamics, as well as electronic band theory, capturing the essence of the light-matter interaction happening among materials, while simplifying the mathematical description. The author uses Python simulation to test the efficacy of this model and observes the steady state absorption rate. Meanwhile, this work also studies the dynamical properties of the system including excited state probability and the expectation value of photon number in the beam. The numerical result is in good accordance with experimental evidence, where similar trends are observed, paving the way for relevant theoretical and experimental researches on the optical properties of graphene and other materials.