Topics in the theory of amorphous materials

In this Colloquium, I describe some current frontiers in the physics of semiconducting amorphous materials and glasses, including a short, but self-contained discussion of techniques for creating computer models, among them the quench from the melt method, the Activation-Relaxation Technique, the decorate and relax method, and the experimentally constrained molecular relaxation scheme. A representative study of an interesting and important glass (amorphous GeSe3:Ag) is provided. This material is a fastion conductor and a serious candidate to replace current FLASH memory. Next, I discuss the effects of topological disorder on electronic states. By computing the decay of the density matrix in real space, and also computing well-localized Wannier functions, we close with a quantitative discussion of Kohn’s Principle of Nearsightedness in amorphous silicon. PACS. 61.43.-j Disordered solids – 61.43.Bn Structural modeling: serial-addition models, computer simulation – 61.43.Fs Glasses – 71.23.Cq Amorphous semiconductors, metallic glasses, glasses – 71.23.An Theories and models; localized states – 66.30.Dn Theory of diffusion and ionic conduction in solids – 71.23.-k Electronic structure of disordered solids