单壁碳纳米管电子输运特性的稳定性分析

基于变形单壁碳纳米管能量色散关系，计算了碳纳米管最低导带的电子速度及有效质量随形变系数变化的各种曲线，以此推测碳纳米管输运性质的稳定性问题.计算结果表明：对于特定类型的碳纳米管，只当其形变发生在某特定方向、且处于低形变（形变系数ε≤002 ）区时，电子平均速度v_mean及平均有效质量m^*_mean随形变改变才会很小（相对改变量≤2%），这意味着此时的碳纳米管低偏压电子输运性能是基本稳定的.而其他形变情形，电子平均速度v_mean或电子平均有效质量m^*_mean或两者随形变变化明显，甚至有跃变，这意味着其低偏压电子输运性能是不稳定的，甚至极不稳定. 关键词： 变形单壁碳纳米管 电子速度 电子有效质量 输运性能稳定性

Analysis on the stability of the electronic transport properties of single-walled carbon nanotubes

Based on energy dispersion relation of the deformed single-walled carbon nanotubes （SWCNTs）, various curves of the electronic velocity and effective mass of the lowest conduction band versus deformation parameters for SWCNTs are computed. It is found that only when a deformation occurs in the special direction（s） and is limited to a region of low deformation （the deformation parameter ε≤002）, the variations of the electronic average velocity v_mean and average effective mass m^*_mean of different types of SWCNTs are very small （the relative variation≤2%）, which suggests that in these cases the electronic transport properties for SWCNTs under a low bias are basically stable. Whereas in other cases the electronic average velocity, or electronic average effective mass, or both of them vary significantly, even change in a dramatic way. This means that the electronic transport properties for SWCNTs under a low bias are unstable, even extremely unstable.