平行耦合双量子点结构的低温输运性质  

Low-temperature Transport Properties in Parallel-coupled Double Quantum Dots Devices

作　　者：谌宝菊[1] 张屏 

机构地区：[1]怀化学院物理与电子信息科学系,湖南怀化418008 [2]湖南职业技术学院,湖南长沙410000

出　　处：《怀化学院学报》2006年第8期57-61,共5页Journal of Huaihua University

基　　金：四川省应用基础研究基金(02GY029-188);四川省教育厅自然科学研究基金(2003A078);怀化学院青年课题基金资助项目.

摘　　要：使用双杂质的Anderson模型的哈密顿量,从理论上研究了一个嵌入并联耦合量子点(DQD)的介观电路在低温情况下的非平衡电子输运性质,并用隶玻色子(slave-boson)平均场近似方法求解了哈密顿.结果表明在低温情况下,这个系统中的Kondo效应、库仑阻塞效应以及外加偏压的复杂相互关系决定了电子的输运性质随偏压的增加,电流先是快速增大而后缓慢增大;随耦合强度的增加,微分电导由Kondo单峰变成Kondo双峰,且峰值降低,双峰距变宽.We theoretically study transport properties in parallel - coupled double quantum dots devices at the low temperature by means of the two - impurity Anderson Hamiltonian and Green functions. It is shown that at the low temperature, these transport properties are not only determined by the competition between the Kondo resonance and Coulomb blockade, but also affected by the bias voltage：with the increase of the bias voltage, the persistent current firstly goes up quickly, and then slowly. With the increase of the coupled strength, the Kondo resonance of the differential conductance becomes double peaks from single peak, the max - peak goes down, and the distance of the double peak becomes broader and broader. Thus, this model might be a candidate for future device applications.

关 键 词：耦合双量子点 KONDO效应 库仑阻塞 微分电导 

分 类 号：O488[理学—固体物理]