Recent developments in tight-binding approaches for nanowires

摘要

Full-band nanowire simulations pose significant computational challenges. Nanowires and nanostructures in general have many interfaces, may be composed of alloys, and feature confinement on a scale of a few tens of nanometers. The empirical tight-binding approach is well-suited for modeling these devices: Its basis consists of atomic-like or-bitals with limited-range interactions and reasonably-sized basis sets can accurately reproduce the bands of a wide range of semiconductors. The method easily accommodates strain and electromagnetic fields. Over the years the application of the tight-binding approach to nanodevices such as superlat-tices and resonant-tunneling diodes has led to the development of many useful computational techniques. Recently, its application to random-alloy nanowire calculations has led to the development of approximate bandstructure methods superior to the Virtual-Crystal Approximation for these nanostructures, and its use in nanowire transmission calculations has led to a highly efficient method for transmission calculations. I discuss tight-binding models generally and then give a more in-depth discussion of the recent developments in tight-binding models as applied to nanowires.