正常金属-分子量子点-超导耦合系统的介观输运  

Mesoscopic transport through a hybrid system with a single molecular dot coupled to normal metal and superconducting leads

作　　者：陈桥[1] 张亚民[2] 

机构地区：[1]湖南工程学院数理系,湘潭411404 [2]北京化工大学北方学院,河北065201

出　　处：《原子与分子物理学报》2011年第5期917-922,共6页Journal of Atomic and Molecular Physics

基　　金：湖南省教育厅优秀青年项目(10B022);湖南省自然科学基金(11JJ4005)

摘　　要：运用非平衡格林函数理论、正则变换以及BCS平均场理论研究了正常金属-分子量子点-超导耦合系统(N-MQD-S)的介观输运,得到了系统的电流公式并选择适当的参数进行了数值计算.数值计算结果表明:电声子耦合强度λ与线宽函数Γ对系统的输运行为有较大影响.当λ增大时,由声子辅助隧穿所产生的共振峰将高于分子量子点自身能级产生的共振峰;当线宽函数Γ增大时,在Andreev反射共振峰的两侧将出现新的边峰.We have investigated the mesoscopic transport through the normal metal-molecule quantum dot-superconductor （N--MQD--S）system by using nonequilibrium Green＇s function and canonical transformation of the electron-phonon interaction. We employ BCS theory to describe the Hamiltonian of the superconducting lead. The coupling strength λ of electron-phonon interaction （EPI） has huge influence on the current. As the λ increases,the peak caused by the phonon-assisted transport is higher than the main peak. This is different from N-- MQD-- N system. We also find that the linewidth function Г affect the transport properties of the system. As the Г increases,side peaks emerge around the peak caused by An- dreev reflection.

关 键 词：分子量子点 电声子相互作用 非平衡格林函数 

分 类 号：O471.1[理学—半导体物理] O488[理学—物理]