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
王辉, 胡贵超, 任俊峰
Wang Hui (王辉), Hu Gui-Chao (胡贵超), Ren Jun-Feng (任俊峰)
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.
中图分类号: (Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields)