CAJ | 학술논문

运用Keldysh格林函数方法,研究了两端联有铁磁电极的A-B环中的双量子点自旋极化输运.研究结果显示,系统的隧穿电流、自旋向上电流、自旋向下电流以及自旋累积明显的受自旋极化强度、外加电压和磁通的影响,并且随着极化强度的增大,在平行与反平行组态下的隧穿电流都减小,另外还出现了自旋分流现象.通过改变磁通,能明显地观察到两条通道的干涉现象.反平行组态下的自旋累积会随着极化强度的增大而增大.
운용Keldysh격림함수방법,연구료량단련유철자전겁적A-B배중적쌍양자점자선겁화수운.연구결과현시,계통적수천전류、자선향상전류、자선향하전류이급자선루적명현적수자선겁화강도、외가전압화자통적영향,병차수착겁화강도적증대,재평행여반평행조태하적수천전류도감소,령외환출현료자선분류현상.통과개변자통,능명현지관찰도량조통도적간섭현상.반평행조태하적자선루적회수착겁화강도적증대이증대.
The spin polarized transport through double quantum dots embedded in one arm of an A-B ring coupled to ferromagnetic leads has been studied in this paper.The Keldysh nonequilibrium Green function method is used to calculate the total tunneling current,the spin up current,the spin down current and the spin accumulation.The magnitude of them can be modulated by adjusting the polarization,the bias voltage and the magnetic flux in parallel and antiparallel configuration.With the spin-polarization strength P increasing,the total tunneling current decreases in both parallel and antiparallel configuration,and the tunneling for spin up and spin down electrons are different in two configurations.By tuning the magnetic flux,obvious interference between the two different paths can be observed.The spin accumulation in both QDs in antiparallel configuration is also investigated,and increases with the increase of P.