双势垒异质结构中自旋相关的散粒噪声

利用Landauer-Büttiker散射理论和传递矩阵方法研究了两端具有铁磁接触的双势垒异质结构(F/DB/F)中自旋相关的散粒噪声。计算结果表明:电流和散粒噪声随阱宽的增加发生周期性的振荡,随着垒厚的增加产生了明显的相位差,与自旋向上电子相比,垒厚对自旋向下电子的电流和散粒噪声影响更大。Rashba自旋轨道耦合强度的增加加大了电流和散粒噪声的振荡频率。偏压的增加减小了电流和散粒噪声的振荡频率,增大了电流和散粒噪声的峰谷比和峰值。电流和散粒噪声随自旋轨道耦合强度和偏压的变化强烈依赖于两铁磁电极中磁化方向的夹角。

Spin-dependent shot noise in double-barrier heterostructures

On the basis of the Landauer-Büttiker scattering formalism and transfer matrix method,we investigate the spin-dependent shot noise properties of electrons tunneling through AlGaAs/GaAs double-barrier heterostructures（DB） sandwiched between two ferromagnets（F） with different relative magnetization direction in the presence of the Rashba spin-orbit interaction and an electric field.The results indicate that the current and shot noise are periodic function of the well width.The phasic difference of the current and shot noise with different spin orientations markedly increase as the barrier thickness increases.As compared with the spin-up electron,the variation of barrier thickness has a higher effect on the current and shot noise of spin-down electron.The oscillation frequencies of the current and shot noise increase with the increase of the Rashba spin-orbit coupling strength.As the external bias voltage increases,the oscillation frequencies of the current and shot noise decrease,and the peak-to-valley ratio and peaks of the current and shot noise increase.The variation of the current and shot noise with increasing spin-orbit coupling strength as well as with increasing bias voltage is strongly dependent on the relative orientation of the two magnetizations in the left and right ferromagnets.