Coherent electron-nuclear coupling in oligothiophene molecular wires
Coherent electron-nuclear coupling in oligothiophene molecular wires
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DOI：
10.1038/nphys1802
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发表时间：
2010-12-01
期刊：
影响因子：
19.6
通讯作者：
Meyer, Gerhard
中科院分区：
文献类型：
--
作者：
Repp, Jascha;Liljeroth, Peter;Meyer, Gerhard
在分子电子学中，单个分子充当电子器件。在这些系统中，电子-振子（e-nu）耦合有望导致新的物理现象和潜在的器件功能（1-3）。在先前对分子线的研究中，e-nu耦合是由于著名的frank - condon原理而发生的，该原理适用于Born-Oppenheimer近似。这意味着在振动激发之后，电子和振动相互独立地演化。在这里，我们表明，当分子中的两个电子能级被分子振动耦合时，这个简单的图像会发生显著变化（4,5）。在分子线中，我们观察到非玻恩-奥本海默状态，电子和核运动的相干耦合出现(6)。这种现象应该发生在所有具有强电子-振动耦合和振动能阶的电子能级间隔的系统中。在分子电子学中，电子和核运动的相干耦合可以用来实现电子输运的机械控制。
In molecular electronics individual molecules serve as electronic devices. In these systems, electron-vibron (e-nu) coupling can be expected to lead to new physical phenomena and potential device functions(1-3). In previous studies of molecular wires, the e-nu coupling occurred as a result of the well-known Franck-Condon principle, for which the Born-Oppenheimer approximation holds. This means that after a vibronic excitation, the electrons and the vibrations evolve independently from each other. Here we show that this simple picture changes markedly when two electronic levels in a molecule are coupled by a molecular vibration(4,5). In molecular wires we observe a non-Born-Oppenheimer regime, for which a coherent coupling of electronic and nuclear motion emerges(6). This phenomenon should occur in all systems with strong electron-vibration coupling and an electronic level spacing of the order of vibrational energies. The coherent coupling of electronic and nuclear motion could be used to implement mechanical control of electron transport in molecular electronics.