中国物理B ›› 2013, Vol. 22 ›› Issue (5): 58504-058504.doi: 10.1088/1674-1056/22/5/058504

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

The effect of dimerization on the magnetoresistance in organic spin valves

王辉, 胡贵超, 任俊峰   

  1. College of Physics and Electronics, Shandong Normal University, Jinan 250014, China
  • 收稿日期:2012-11-06 修回日期:2012-12-09 出版日期:2013-04-01 发布日期:2013-04-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 10904084 and 10904083) and the Shandong Province Middle-Aged and Young Scientists Research Awards Foundation, China (Grant No. 2009BS01009).

The effect of dimerization on the magnetoresistance in organic spin valves

Wang Hui (王辉), Hu Gui-Chao (胡贵超), Ren Jun-Feng (任俊峰)   

  1. College of Physics and Electronics, Shandong Normal University, Jinan 250014, China
  • Received:2012-11-06 Revised:2012-12-09 Online:2013-04-01 Published:2013-04-01
  • Contact: Hu Gui-Chao E-mail:hgc@sdnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 10904084 and 10904083) and the Shandong Province Middle-Aged and Young Scientists Research Awards Foundation, China (Grant No. 2009BS01009).

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摘要： The effect of lattice dimerization on the magnetoresistance (MR) in organic spin valves is investigated based on the Su-Schrieffer-Heeger (SSH) model and the Green's function method. By comparing with the results for a uniform chain, we find that the dimerization of the molecular chain modifies the monotonic dependence of the MR on the bias to an oscillatory one. A sign inversion of the MR is observed when the amplitude of the dimerization is adjusted. The results also show that at a low bias, the MR through a dimerized chain decreases with the increasing bias as well as the increasing chain length, which is consistent with the experimental reports. A further understanding can be achieved by analyzing the electronic states and the spin-dependent transmission spectrum with the parallel and antiparallel magnetization orientations of the two ferromagnetic electrodes.

关键词: organic spintronics, magnetoresistance, dimerization

Abstract: The effect of lattice dimerization on the magnetoresistance (MR) in organic spin valves is investigated based on the Su-Schrieffer-Heeger (SSH) model and the Green's function method. By comparing with the results for a uniform chain, we find that the dimerization of the molecular chain modifies the monotonic dependence of the MR on the bias to an oscillatory one. A sign inversion of the MR is observed when the amplitude of the dimerization is adjusted. The results also show that at a low bias, the MR through a dimerized chain decreases with the increasing bias as well as the increasing chain length, which is consistent with the experimental reports. A further understanding can be achieved by analyzing the electronic states and the spin-dependent transmission spectrum with the parallel and antiparallel magnetization orientations of the two ferromagnetic electrodes.

Key words: organic spintronics, magnetoresistance, dimerization

中图分类号:  (Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields)

  • 85.75.-d
73.61.Ph (Polymers; organic compounds) 75.47.-m (Magnetotransport phenomena; materials for magnetotransport)