HgTe量子点体系中的电子输运

Electron Transport in HgTe Quantum Dots System

文章为探究HgTe量子点和传统半导体量子点的性能优劣,理论上研究HgTe量子点的电子性质,利用非平衡格林函数方法,研究了两个铁磁电极之间的HgTe量子点在小偏压下的电流输运性质,并将其与传统半导体量子点进行比较。研究发现,对于HgTe量子点体态,其电子性质与输运性质与传统半导体量子点类似;对于HgTe量子点边缘态,量子点边缘处的电子可以延伸到量子点的中心,从而在小偏压下就会产生电流,导致HgTe量子点的输运性能优于传统半导体量子点。同时,输运电导会随着量子点的半径减小、温度增高而减小。

In order to explore the performance of HgTe quantum dots and traditional semiconductor quantum dots,this paper theoretically investigates the electronic properties of HgTe topological insulator quantum dots.Through nonequilibrium Green's-function method,the current transport properties of HgTe quantum dots between two ferromagnetic electrodes under small bias voltage are studied and compared with traditional semiconductor quantum dots.It is found that the electronic and transport properties of HgTe quantum dots are similar to those of traditional semiconductor quantum dots;For the edge state of HgTe quantum dots,the electrons at the edge of the quantum dot can extend to the center of the quantum dot,and a current will be generated under a small bias voltage,resulting in the transport properties of HgTe quantum dots better than that of traditional semiconductor quantum dot.At the same time,the transport conductance decreases as the radius of the quantum dot decreases and the temperature increases.