摘要
从非平衡格林函数出发 ,推导了有外加偏压和抽运信号同时存在时 ,分子器件与两个正常导线形成的系统的电流电压公式 ,并对由纳米碳管 (CNT)作为分子器件的系统 (N CNT N)进行了数值计算 .通过对加在碳管上两个门电压的周期性改变 ,系统中产生稳定的直流抽运电流 ,发现只有借助CNT的电子能级才能得到明显的抽运电流 ,电流大小随抽运信号增强而增加 .随着费米能级的改变 ,抽运电流方向可以反向 .有外加偏压时 ,电流的形成除由抽运信号驱动外 ,还受到外偏压驱动 .
Based on non equilibrium Greens function, we derived the formula for the total current of molecular device system in the presence of both pumping potential and external bias and applied our formula to the armchair carbon nanotube (CNT) based system (N CNT N). It is found that a dc current can be pumped out evidently from such molecular device by a cyclic variation of two gate voltages near nanotube only when the Fermi level is near the energy levels of CNT. Large pumped current can be generated by increasing the pumping amplitude and the pumped current can be either positive or negative. In the presence of external bias, the current is driven by both the pumping potential and the external bias.
出处
《深圳大学学报（理工版）》
EI
CAS
2002年第4期10-16,共7页
Journal of Shenzhen University(Science and Engineering)
基金
教育部留学回国人员科研基金资助项目 (2 0 0 2 - 2 4 7)
