Hu F M, Kou Liangzhi, Frauenheim Thomas
Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1a, D-28359 Bremen, Germany.
Sci Rep. 2015 Mar 10;5:8943. doi: 10.1038/srep08943.
Two magnetic impurities on the edge of a zigzag graphene nanoribbon strongly interact with each other via indirect coupling, which can be mediated by conducting carriers. By means of Quantum Monte Carlo (QMC) simulations, we find that the spin-orbit coupling λ and the chemical potential μ in system can be used to drive the transition of local-spin exchange from ferromagnetism to anti-ferromagnetism. Since the tunable ranges for λ and μ in graphene are experimentally reachable, we thus open the possibilities for its device application. The symmetry in spatial distribution is broken by the vertical and the transversal spin-spin correlations due to the effect of spin-orbit coupling, leading to the spatial anisotropy of spin exchange, which distinguish our findings from the case in normal Fermi liquid.
锯齿形石墨烯纳米带边缘的两个磁性杂质通过传导载流子介导的间接耦合强烈相互作用。通过量子蒙特卡罗（QMC）模拟，我们发现系统中的自旋轨道耦合λ和化学势μ可用于驱动局部自旋交换从铁磁性到反铁磁性的转变。由于石墨烯中λ和μ的可调范围在实验上是可以实现的，因此我们为其器件应用开辟了可能性。由于自旋轨道耦合的影响，垂直和横向自旋 - 自旋相关性打破了空间分布的对称性，导致自旋交换的空间各向异性，这使我们的发现有别于正常费米液体中的情况。
