中国物理B ›› 2020, Vol. 29 ›› Issue (12): 127201-.doi: 10.1088/1674-1056/abc0e4

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  • 收稿日期:2020-07-13 修回日期:2020-09-22 接受日期:2020-10-14 出版日期:2020-12-01 发布日期:2020-11-26

Different noncollinear magnetizations on two edges of zigzag graphene nanoribbons

Yang Xiao(肖杨)1,†, Qiaoli Ye(叶巧利)1,†, Jintao Liang(梁锦涛)1, Xiaohong Yan(颜晓红)2, and Ying Zhang(张影)1,‡   

  1. 1 College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China; 2 School of Material Science and Engineering, Jiangsu University, Zhenjiang 212013, China
  • Received:2020-07-13 Revised:2020-09-22 Accepted:2020-10-14 Online:2020-12-01 Published:2020-11-26
  • Contact: These authors contributed equally. Corresponding author. E-mail: yingzhang@nuaa.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. NSFC11804158, NSFC61974067, NSFC91750112, and NSFC11947101).

Abstract: Based on density functional theory and non-equilibrium Green's function method, we studied noncollinear magnetism and spin transport in a 180° domain wall made of zigzag graphene nanoribbon (ZGNR) with different noncollinear magnetic profiles on the top and bottom edges. Our results show that a helical domain wall on the top (bottom) edge and an abrupt domain wall on the bottom (top) edge can survive in the ZGNR. This indicates that such characteristic magnetization distribution can be obtained by some means, e.g., the introduction of impurity on one edge. Compared to a wide ZGNR, a narrow ZGNR presents obvious coupling between the two edges which changes the magnetization and transmission greatly. As for the above-mentioned distinct magnetic profile, the spin transport is blocked in the abrupt domain wall due to strong spin flip scattering while remains unaffected in the helical domain wall due to the spin mixing effect. We deduce a formula of the transmission for various magnetic profiles of the ZGNRs. A new result based on this formula is that the transmission at the Fermi level can be zero, one, and two by tuning the edge magnetization. Our results provide insights into the noncollinear spin transport of the ZGNR-based devices.

Key words: graphene nanoribbon, spintronic transport, density functional theory, nonequilibrium Green's function

中图分类号:  (Theory of electronic transport; scattering mechanisms)

  • 72.10.-d
85.65.+h (Molecular electronic devices) 73.63.-b (Electronic transport in nanoscale materials and structures)