石墨烯中Dirac费米子量子输运特性研究

Study on quantum transport properties of graphene Dirac fermions

利用紧束缚模型的方法研究了石墨烯中Di-rac费米子的势垒相关输运特性,分析了石墨烯中Di-rac费米子的势垒透射率与其入射角度、入射能量、势垒高度和势垒厚度等对应关系。通过理论分析和数值计算表明,石墨烯中Dirac费米子的隧穿系数随矩形势垒的高度和厚度的变化都呈现出明显的振荡效应,隧穿系数与入射角度依赖关系证实了Klein效应。在一定参数下,Dirac费米子的势垒透射率随Dirac费米子入射能量的变化经历从"0"～"1"的突变,显示良好的"电导开关效应",该效应在微电子器件中将有很好的应用前景。

We studied the graphene Dirac fermions barrier-dependence transport properties by using tight-bind ing model method. Taking account of graphene Dirae fermions ineident angle, incident energy and the barrier height or barrier thickness, we analyzed the graphene Dirac fermions transmission coefficient of the barrier. Theoretical analysis and numerical calculations show that the tunneling coefficient of Dirac fermions in graphene appears a clear oscillation effect with height and thickness of the square barrier varing, and the dependence of tunneling coefficient and incident angle confirms Klein effects. Dirac fermions barrier transmission rate vaies form 0 to 1 with certain parameters as Dirac fermions of the incident energy changes. The change of conductance appears good ＂conductance switching effect＂, and this effect will have a good application prospect on microelec- tronic devices.