锯齿形石墨烯纳米带特性的理论研究

The Theoretical Research on Characteristics of Zigzag Graphene Nanoribbons

对具有一定宽度的锯齿形石墨烯纳米带用对角化其哈密顿的方法自洽地计算了电子在半填满的情况下石墨烯的性质,结果发现:锯齿形石墨烯带在相同条件下两边之间是铁磁耦合还是反铁磁耦合是随机的.两边之间呈现反铁磁序时,石墨烯带是半导体,其带隙具有量子限制效应;呈现铁磁序时,石墨烯带是导体.无论哪一种情况,石墨烯带边缘原子的磁序都是一个定值,并不随系统大小而变化,这就为石墨烯作为自旋电子学的材料提供了一个无比优越的条件.

The properties of zigzag edges of graphene nanoribbons with different widths are self- consistently calculated by the method of diagonalizing the hamiltonian. The results show that appearance of ferromagnetism or antiferromagnetism in two edges of the nanoribbon is random at the same condition. The ribbons is semiconductor and the band gap has a quantum confinement effect with the appearance of antiferromagnetic order between the two sides. The ribbons is con- ductor with the appearance of ferromagnetic order. In either case, the magnetic order of atoms along edges is a constant value, and it does not change with the size of system. All of these provide an incomparably superior condition for taking graphene as the material of spintronics.