Agapito Luis A, Kioussis Nicholas
Department of Physics and W. M. Keck Computational Materials Theory Center, California State University Northridge, Northridge, CA 91330, USA.
J Phys Chem C Nanomater Interfaces. 2011 Jan 24;115(6):2874-2879. doi: 10.1021/jp1096234.
Magnetism in graphene nanofragments arises from the spin polarization of the edge-states; consequently, as the material inexorably shrinks, magnetism will become a dominant feature whereas the bulk carrier mobility will be less relevant. We have carried out an ab initio study of the role of graphene-ultra-nanofragment magnetism on electronic transport. We present, as a proof-of-concept, a nanoscopic spin-polarized field-effect transistor (FET) with the channel and metallic contacts carved from a single graphene sheet. We demonstrate the selective tuning of conductance through electric-field control of the magnetic, rather than the charge, degrees of freedom of the channel, the latter typically employed in microscopic graphene FETs.
石墨烯纳米片段中的磁性源于边缘态的自旋极化；因此，随着材料不断收缩，磁性将成为主要特性，而整体载流子迁移率的相关性将降低。我们对石墨烯超纳米片段磁性在电子输运中的作用进行了从头算研究。作为概念验证，我们展示了一种纳米级自旋极化场效应晶体管（FET），其沟道和金属接触由单个石墨烯片材雕刻而成。我们通过电场控制沟道的磁自由度而非电荷自由度来证明电导的选择性调谐，电荷自由度通常用于微观石墨烯FET中。
