Switching, Dual Spin-Filtering Effects, and Negative Differential Resistance in a Carbon-Based Molecular Device
Switching, Dual Spin-Filtering Effects, and Negative Differential Resistance in a Carbon-Based Molecular Device
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碳基分子器件中的开关、双自旋过滤效应和负微分电阻
DOI：
10.1021/jp2092576
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发表时间：
2012-01-26
影响因子：
3.7
通讯作者：
Zhou, Guanghui
中科院分区：
文献类型：
--
作者：
Wan, Haiqing;Zhou, Benhu;Zhou, Guanghui
我们提出了一个分子器件中自旋相关的电子输运的从头计算方法，该分子器件由两个苯环封端的碳链构成，该碳链夹在两个锯齿形边缘的石墨烯纳米颗粒（ZGNR）电极之间，其中ZGNR由外部磁场调制。利用碳π电子理论证明了模型器件中开关、双自旋过滤效应和负微分电阻（NDR）的共存性。有趣的是，通过改变苯环平面和电极平面之间的取向可以实现双态分子构象开关，在所考虑的偏压窗口内，多数自旋电流调制（ON/OFF比）为170-479。此外，该器件还具有良好的双自旋过滤效应，可以通过源漏电压或电极的磁结构产生和控制完全的双自旋极化电流。选择性自旋电流的产生是由于双选择规则、两个ZGNR电极自旋通道之间的对称性匹配以及碳链的自旋选择。此外，在我们的模型中也观察到了明显的NDR行为。
We present ab initio calculations for spin-dependent electron transport in a molecular device constructed by two carbon chains capped with a phenyl ring, which is sandwiched between two zig-zag-edged graphene nanoribbon (ZGNR) electrodes, where the ZGNRs are modulated by external magnetic field. The coexistence of switching, dual spin-filtering effects, and negative differential resistance (NDR) in the model device is demonstrated with the theory of carbon pi-electrons. Interestingly, a two-state molecular conformational switch can be realized by changing the orientation between the planes of phenyl ring and electrodes, where the majority-spin current modulation (ON/OFF ratio) is 170-479 within the considered bias window. Moreover, the device shows perfect dual spin-filtering effect and can generate and control a full dual spin-polarized current through either the source-drain voltage or magnetic configuration of the electrodes. The selective spin current is due to a dual selection rule, the symmetry match between two ZGNR electrodes spin channel, and the carbon chain's spin selection in our system. In addition, the obvious NDR behavior has also been observed in our model.