The effect of dimerization on the magnetoresistance in organic spin valves  

作　　者：王辉 胡贵超 任俊峰 

机构地区：[1]College of Physics and Electronics,Shandong Normal University

出　　处：《Chinese Physics B》2013年第5期614-619,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos. 10904084 and 10904083);the Shandong Provincial Middle-Aged and Young Scientists Research Awards Foundation, China (Grant No. 2009BS01009)

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.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 

分 类 号：TN01[电子电信—物理电子学]