Graphene Spin Electron Transport Properties Of Nanometer Structure Research

This thesis describes a serial of interesting phenomena of electronic and spin transport in graphene nano-structures. Using Single-particle Green’s function and self-consistent calculation, this thesis gives some valuable results about electronic and spin transport in several kinds of graphene nano-structures.This is mainly divided into following chapters:the first chapter describes the basic concepts of graphene, the academic developments of graphene in electronic devices, as well as some hot issues about this area. The second chapter give the detailed formulism and numerical algorithms about transport property graphene, including Single-particle Green’s function, Landauer—Buttiker formula and self-consistent calculation for spin-related transport. The third chapter gives transport properties of defective graphene zigzag ribbon, multi-leads hexagonal graphene dots, which include the situations about both single layer and bilayer. From the results, the overlap between two nano-circuits leads to strong coupling interactions, which can be used to design more effective electronic nano-circuits. The last chapter intensively describes the spin transport in graphene structures and a Spin-switch device based on Dumbbell-shaped graphene nanoislands. Controlling the spin configurations of the device can realize the efficient electronic transport for electrons with specific spin, which actually is a spin switch. Here due to the size of the model is small, the requisite magnetic field to make the transition between ON/OFF states work is so large. However, with proper temperature and size of the model, this design is enlightening for future graphene logic circuits and area of memory.