边缘势效应对电子输运性质的影响

Influence of Edge Potential Effect on the Transport Properties of Electrons

研究了磁场及无序杂质存在条件下,边缘势效应对磁场下二维无序杂质系统中的电子输运性质的影响.边缘势越小,电子输运通道越容易打开,电导“台阶”越易向能量小的区域平移;边缘势较大,电子需要较大的费米能才能打开一个量子通道,电导“台阶”越向右平移;边缘势一大一小时,“台阶”有先左后右的平移趋势.系统电导随着磁场的变化表现出周期性振荡行为,系统电导的极值也随边缘势的变大而减小.受杂质散射的影响,系统电导随无序杂质质量百分数的增大而减小.

In the 2D impurity system,we study the effect of edge potential influence on the conductance with the existence of magnetic field and impurity.The smaller the edge potential is,the easier the electron transport channel is opened,and the conductance“step”moves to the smaller energy region;when the edge potential is large,the electrons need more Fermi energy to open a quantum channel,and the conductance“step”shifts to the right;when there are two edge potentials,a large one and a smaller one,and the“step”moves to the left first,and then to the right.The conductance exhibits periodic oscillation with the external magnetic field,the extremum of the conductance decreases with the increase of the edge potential.With the increase of the impurity concentration,the conductance decreases.