Guo Yan-Dong, Liu Hui-Feng, Zeng Hong-Li, Yan Xiao-Hong, Song Xiao-Chen
College of Electronic and Optical Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China and Key Laboratory of Radio Frequency and Micro Nano Electronics of Jiangsu Province, Nanjing 210023, China.
Key Laboratory of Radio Frequency and Micro Nano Electronics of Jiangsu Province, Nanjing 210023, China and College of Natural Science, Nanjing University of Posts and Telecommunications, Nanjing 210046, China.
Phys Chem Chem Phys. 2018 Apr 4;20(14):9241-9247. doi: 10.1039/C7CP08337H.
Unlike graphene nanoribbons, zigzag monolayer hexagonal boron nitride nanoribbons (ZBNNRs) possess two distinct edges (B and N edges). Using first-principles calculations, we investigate the spin-dependent electronic transport of ZBNNRs with edge defects. It is found that the defects could make the system operate as a dual spin filter, where the direction of spin polarization is switched by the defect. Further analysis shows that the transmission eigenchannels for the opposite spins reside spatially separated on opposite edges. The defect on one edge could suppress the transmission for only one spin component, but preserve that for the other spin, resulting in a dual spin filter effect. This effect is found to be unaffected by the width of the ribbon and the length of the defect. Moreover, by constructing defects on both edges, the system exhibits two transmission peaks with opposite spins residing discretely on both sides of the Fermi level, suggesting that an electrically controlled dual spin filter based on ZBNNRs is also realizable. As controllable defects have been experimentally fabricated on monolayer boron nitride [T. Pham, A. L. Gibb, Z. Li, S. M. Gilbert, C. Song, S. G. Louie and A. Zettl, Nano Lett., 2016, 16, 7142-7147], our results may shed light on the development of B/N-based spintronic devices.
与石墨烯纳米带不同，锯齿形单层六方氮化硼纳米带（ZBNNRs）具有两个不同的边缘（B边缘和N边缘）。我们使用第一性原理计算研究了具有边缘缺陷的ZBNNRs的自旋相关电子输运。结果发现，这些缺陷可使系统作为双自旋过滤器运行，其中自旋极化方向由缺陷切换。进一步分析表明，相反自旋的传输本征通道在空间上位于相对的边缘。一个边缘上的缺陷仅能抑制一个自旋分量的传输，但保留另一个自旋的传输，从而产生双自旋过滤效应。发现这种效应不受纳米带宽度和缺陷长度的影响。此外，通过在两个边缘上构建缺陷，系统在费米能级两侧离散地呈现出两个具有相反自旋的传输峰，这表明基于ZBNNRs的电控双自旋过滤器也是可实现的。由于在单层氮化硼上已经通过实验制造出了可控缺陷[T. Pham, A. L. Gibb, Z. Li, S. M. Gilbert, C. Song, S. G. Louie和A. Zettl, Nano Lett., 2016, 16, 7142 - 7147]，我们的结果可能为基于B/N的自旋电子器件的发展提供启示。
