Precursor configurations and post-rupture evolution of Ag-CO-Ag single-molecule junctions
Precursor configurations and post-rupture evolution of Ag-CO-Ag single-molecule junctions
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DOI：
10.1039/c4nr04645e
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发表时间：
2014-01-01
期刊：
影响因子：
6.7
通讯作者：
Halbritter, Andras
中科院分区：
文献类型：
--
作者：
Balogh, Zoltan;Visontai, David;Halbritter, Andras
用实验关联分析和第一性原理理论研究了Ag-Co-Ag单分子结形成前和断裂后的结构和演化。二维相关直方图和条件直方图表明，在单分子桥构型之前，CO分子已经平行于银单原子接触。与纯银单原子结的单通道输运相比，这种分子前驱体构型伴随着额外的电导通道的开放。为了研究结破裂后的演化，我们引入了开口和随后闭合的电导迹线之间的互相关分析。这一分析表明，该分子严格结合在一个电极的顶端，因此当连接关闭时，重新建立了相同的单分子构型。实验结果被接触几何、传输本征值和散射波函数演化的从头算模拟所证实。
Experimental correlation analysis and first-principles theory are used to probe the structure and evolution of Ag-CO-Ag single-molecule junctions both before the formation and after the rupture of the junctions. Two dimensional correlation histograms and conditional histograms demonstrate that prior to the single-molecule bridge configuration the CO molecule is already bound parallel to the Ag single-atom contact. This molecular precursor configuration is accompanied by the opening of additional conductance channels compared to the single-channel transport in pure Ag monoatomic junctions. To investigate the post-rupture evolution of the junction we introduce a cross-correlation analysis between the opening and the subsequent closing conductance traces. This analysis implies that the molecule is bound rigidly to the apex of one electrode, and so the same single-molecule configuration is re-established as the junction is closed. The experimental results are confirmed by ab initio simulations of the evolution of contact geometries, transmission eigenvalues and scattering wavefunctions.