The Research Of The Quantum Transport Properties Of The Low Dimensional Mesoscopic System

Mesoscopic system is the system the scales of which between the macroscopic and microscopic system. The narrow sense of mesoscopic system is refers to the system its scale is smalland is characteristicted by the quantum mechanica of electronic sports;and the broadest sense of the mesoscopic system includes the atomic and molecular mass, nanometer materials etc.In mesoscopic system, many transport phenomena can be observed which is completely different from classic systeml.This article mainly researched the electronic transport properties of the mesoscopic system of low dimensional theorical.by useing Landauer formulation and the green’s function method under tight-binding approximation.First is the introduction, we gave the definition of the mesoscopic system,and also introduced the research situation at present.the basic properties of the system and the related experimental prospects.Then we introduced the continuous current of the metal ring,pervasive conductivity fluctuation,AB effect and AAS effect.Based on the knowladge above,two typical low dimensional mesoscopic system are introduced, one is single-walled carbon nanotubes, which can be think as quantum line; the other is a mesoscopic golden ring, which can be think as the equivalent of a line composed of quantum dots.Use Landauer transport theory and the unbalanced green’s function method under tight-binding approximation,we researched the transport properties of single-walled carbon nanotubes and the little gold ring,discussed the quantum conduction of the single-walled under different coupling effict between carbon nanotubes and electrical contacts.The results showed that, under strong coupling strength, the system performanced like a Fabry-Perot electronic resonator, in which obvious quantum oscillation can be observed; and for the weak coupling effect, the system achieve to the limit of quantum conductivity oscillation, acting like a quantum dots.