具有边缘缺陷石墨烯纳米结的自旋输运特性(英文)

The spin-dependent transport properties of a zigzag graphene nanoribbon edge-defect junction

利用第一性原理研究了两种具有边缘缺陷石墨烯纳米结的自旋输运,即边界氢原子饱和和未被饱和两种情况。结果表明:边缘缺陷改变了电子的输运行为。对于完整的石墨烯纳米带,两种自旋的电子在费米能级附近是完全简并的;对于含有边缘缺陷的石墨烯纳米结,两种自旋的电子在费米能级附近的很大能量范围内表现出自旋分离。电子局域态密度可进一步说明这种输运行为。这些纳米结可产生与自旋相关的极化电流。特别对于未饱和的缺陷结,在任何偏压下都有较高的自旋滤波效率。

First-principles calculation was performed to investigate the transport properties of edge-defect junctions of graphene with H-terminated or bare edges, which were generated by removing edge carbon atoms from a perfect ribbon. The edge defect changes the electronic transport behavior of a zigzag graphene nanoribbon from spin-degenerated for a perfect ribbon to highly spin-polarized for edge-defective ones at the Fermi level. The electronic local density of states isosurface calculations could help understand the transport results. These junctions could generate spin-polarized currents. Especially, the bare edge-defect junction has a high spin filter efficiency regardless of the external bias. This behavior suggests a Dossible use of the edge-defective ~raDhene in a snin filter system.