Andreev reflection current through a molecule quantum dot in the presence of the electron-phonon interaction and the spin-flip scattering
Andreev reflection current through a molecule quantum dot in the presence of the electron-phonon interaction and the spin-flip scattering
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DOI：
10.1016/j.physleta.2010.11.042
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发表时间：
2011-01-17
影响因子：
2.6
通讯作者：
Jiang, Liang
中科院分区：
文献类型：
--
作者：
Bai, Long;Zhang, Zheng-Zhong;Jiang, Liang
借助于非平衡格林函数和Lang-Firsov正则变换，我们研究了铁磁/单分子量子点/超导(FM/MQD/SC)系统中声子环境和自旋反转散射对Andreev反射(AR)的联合影响。在强电子-声子相互作用(EPI)的存在下，发现EPI对AR电流(称为Franck-Condon阻塞)有强烈的抑制作用。当在MQD中考虑相干自旋翻转(类似于横向磁场)时，AR电流显著增强，进而可以产生自旋极化的AR电流，甚至是纯自旋极化的AR电流。通过调节系统参数，可以改变AR电流的大小和方向，为AR过程的控制提供了一种有效的机制。(C)2010爱思唯尔B.V.保留所有权利。
With the aid of the nonequilibrium Green's function and the Lang-Firsov canonical transformation, we investigate the joint effects of a phononic environment and the spin-flip scattering on the Andreev reflection (AR) in a ferromagnet/single-molecular quantum dot/superconductor (FM/MQD/SC) system. In the presence of the strong electron-phonon interaction (EPI), it is found that the EPI strongly suppresses the AR current (called the Franck-Condon blockade). When the coherent spin-flip (similar to a transverse magnetic field) is taken into account within the MQD, the AR current is significantly enhanced, furthermore, the spin-polarized AR current or even the pure spin-polarized AR current can be generated. By tuning the system parameters, the amplitude and direction of the AR current can be changed, this provides an efficient mechanism for controlling the AR process. (C) 2010 Elsevier B.V. All rights reserved.