García-Fuente A, Gallego L J, Vega A
Department of Chemistry, University of Fribourg, CH-1700 Fribourg, Switzerland. Departamento de Física Teórica, Atómica y Óptica, Universidad de Valladolid, E-47011 Valladolid, Spain.
J Phys Condens Matter. 2015 Apr 10;27(13):135301. doi: 10.1088/0953-8984/27/13/135301. Epub 2015 Mar 13.
By means of density-functional-theoretic calculations, we investigated the structural, electronic and transport properties of hydrogen-passivated zigzag graphene nanoribbons (ZGNRs) on which a one-atom-thick Mo chain was adsorbed (with or without one or two missing atoms), or in which the passivating hydrogen atoms were replaced by Mo atoms. Mo-passivated ZGNRs proved to be nonmagnetic. ZGNRs with an adsorbed defect-free Mo chain were most stable with the Mo atoms forming dimers above edge bay sites, which suppressed the magnetic moments of the C atoms in that half of the ribbon; around the Fermi level of these systems, each spin component had a transmission channel via the Mo spz band and one had an additional channel created by polarization of the ZGNR π* band, leading to a net spin current. The absence of an Mo dimer from an Mo chain adsorbed at the ZGNR edge made the system a perfect spin filter at low voltage bias by suppressing the Mo spz band channels. Thus this last kind of hybrid system is a potential spin valve.
通过密度泛函理论计算，我们研究了氢钝化锯齿形石墨烯纳米带（ZGNRs）的结构、电子和输运性质，在该纳米带上吸附了一个单原子厚的Mo链（有或没有一个或两个缺失原子），或者其中钝化氢原子被Mo原子取代。Mo钝化的ZGNRs被证明是非磁性的。吸附有无缺陷Mo链的ZGNRs最稳定，Mo原子在边缘湾位上方形成二聚体，这抑制了纳米带该半部分中C原子的磁矩；在这些系统的费米能级附近，每个自旋分量都有一个通过Mo spz带的传输通道，并且有一个由ZGNR π*带极化产生的额外通道，导致净自旋电流。吸附在ZGNR边缘的Mo链中没有Mo二聚体，通过抑制Mo spz带通道，使该系统在低电压偏置下成为完美的自旋过滤器。因此，最后这种混合系统是一种潜在的自旋阀。
