论文标题
带有Rashba自旋轨耦合的单层石墨烯中的手性隧穿：自旋电流
Chiral tunneling in single layer graphene with Rashba spin-orbit coupling: spin currents
论文作者
论文摘要
我们通过均匀的Rashba旋转式轨道偶联（强度λ），在单层石墨烯中通过1D矩形屏障{\ varepsilon}> 0在Fermi Energy {\ Varepsilon}> 0上的2D无质量狄拉克电子的向前散射（\ varepsilon}> 0）研究。因此暴露了克莱因悖论在石墨烯旋转中的作用。结果表明，（1）对于{\ varepsilon} - 2λ<{u_0} <{\ varepsilon} +2λ有部分klein隧道，其中，传输范围为1，相当明显地，对于小λ_0} {λ_0} { /λ_0} {\ y} 0.1时，范围很大，几乎是散布的范围。 {\ varepsilon} = {u_0}。 （2）旋转密度和自旋 - 电流密度与散装单层石墨烯中预测的这些可观察到的物质明显不同。特别是，它们对λ和{u_0}敏感。 （3）自旋电流密度取决于空间，这意味着发生非零自旋扭矩密度。这样的系统可以用作基于石墨烯的自旋装置，而无需使用外部磁场或磁性材料。
We study forward scattering of 2D massless Dirac electrons at Fermi energy {\varepsilon} > 0 in single layer graphene through a 1D rectangular barrier of height {u_0} in the presence of uniform Rashba spin-orbit coupling (of strength λ). The role of the Klein paradox in graphene spintronics is thereby exposed. It is shown that (1) For {\varepsilon} - 2λ < {u_0}< {\varepsilon} + 2λ there is partial Klein tunneling, wherein the transmission is bounded by 1 and, quite remarkably, for small λ > {λ_0} {\approx} 0.1 meV, the transmission nearly vanishes when the scattering energy equals the barrier height, {\varepsilon}={u_0}. (2) Spin density and spin-current density are shown to be remarkably different than these observables predicted in bulk single layer graphene. In particular, they are sensitive to λ and {u_0}. (3) Spin current densities are space dependent, implying the occurrence of non-zero spin torque density. Such a system may serve as a graphene based spintronic device without the use of an external magnetic field or magnetic materials.
