局部扭转形变下金纳米线的力电响应

Electromechanical Response of Gold Nanowire under Local Torsional Deformation

采用密度泛函理论和非平衡格林函数方法相结合的研究方案,系统考察了局部扭转形变对金纳米线力电特性的影响.结果表明,随着局部扭转角度的增加,金纳米线的形变区域先后经历了弹性形变和塑性形变;在弹性形变过程中,金纳米线的量子输运特性能够得到很好的保持,伏安特性曲线也不受扭转形变的影响;而在塑性形变中,纳米线的平衡电导和给定电压下的电流均比弹性形变时有显著下降.对输运谱的分析阐明了上述现象的物理机制.

The mechanical and electrical properties of gold nanowire under local torsional deformation have been investigated using a combined formalism of density functional theory and nonequilibrium Green＇ s function. It is shown that with increasing torsional angle, the deformed region of nanowire undergoes the elastic and plastic deformation. During the elastic deformation, the transport properties of nanowire can be retained very well, while the plastic deformation has a significant effect on the conductance value and the current-voltage characteristic. The underlaid physical mechanism is discussed.