Hedayati Kh Hamed, Faizabadi Edris
School of Physics, Iran University of Science and Technology, 1684613114 Tehran, Iran.
J Phys Condens Matter. 2018 Feb 28;30(8):085303. doi: 10.1088/1361-648X/aaa5e6.
In this paper, spin-dependent dwell time, spin Hartman effect and spin-dependent conductance were theoretically investigated through a rectangular barrier in the presence of an exchange field by depositing a ferromagnetic insulator on the phosphorene layer in the barrier region. The existence of the spin Hartman effect was shown for all energies (energies lower than barrier height) and all incident angles in phosphorene. We also compared our results of the dwell time in the phosphorene structure with similar research performed on graphene. We reported a significant difference between the tunneling time values of incident quasiparticles with spin-up and spin-down. We found that the barrier was almost transparent for incident quasiparticles with a wide range of incident angles and energies higher than the barrier height in phosphorene. We also found that the maximum spin-dependent transmission probability for energies higher than barrier height does not necessarily occur in the zero incident angle. In addition, we showed that the spin conductance for energies higher (lower) than barrier height fluctuates (decays) in terms of barrier thickness. We discovered that, in contrast to graphene, the Klein paradox does not occur in the normal incident in the phosphorene structure. Furthermore, the results demonstrated the achievement of good total conductance at certain thicknesses of the barrier for energies higher than the barrier height. This study could serve as a basis for investigations of the basic physics of tunneling mechanisms and also for using phosphorene as a spin polarizer in designing nanoelectronic devices.
在本文中,通过在势垒区域的磷烯层上沉积铁磁绝缘体,在存在交换场的情况下,对穿过矩形势垒的自旋相关驻留时间、自旋哈特曼效应和自旋相关电导进行了理论研究。在磷烯中,对于所有能量(低于势垒高度的能量)和所有入射角,都证明了自旋哈特曼效应的存在。我们还将磷烯结构中驻留时间的结果与对石墨烯进行的类似研究进行了比较。我们报道了自旋向上和自旋向下的入射准粒子的隧穿时间值之间存在显著差异。我们发现,对于具有广泛入射角且能量高于磷烯中势垒高度的入射准粒子,势垒几乎是透明的。我们还发现,对于能量高于势垒高度的情况,最大自旋相关传输概率不一定出现在零入射角处。此外,我们表明,对于能量高于(低于)势垒高度的情况,自旋电导随势垒厚度波动(衰减)。我们发现,与石墨烯不同,在磷烯结构中垂直入射时不会出现克莱因佯谬。此外,结果表明在势垒的某些厚度下,对于能量高于势垒高度的情况可以实现良好的总电导。这项研究可以作为研究隧穿机制基本物理的基础,也可以作为在设计纳米电子器件时将磷烯用作自旋极化器的基础。