Magyarkuti A, Balogh Z, Mezei G, Halbritter A
Department of Physics, Budapest University of Technology and Economics, Budafoki ut 8, 1111 Budapest, Hungary.
MTA-BME Condensed Matter Research Group, Budafoki ut 8, 1111 Budapest, Hungary.
J Phys Chem Lett. 2021 Feb 25;12(7):1759-1764. doi: 10.1021/acs.jpclett.0c03765. Epub 2021 Feb 11.
We study the vulnerability of single-molecule nanowires against a temporary disconnection of the junction. To this end, we compare the room and low-temperature junction formation trajectories along the opening and closing of gold-4,4'-bipyridine-gold single-molecule nanowires. In the low-temperature measurements, the cross-correlations between the opening and subsequent closing conductance traces demonstrate a strong structural memory effect: around half of the molecular opening traces exhibit similar, statistically dependent molecular features as the junction is closed again. This means that the junction stays rigid and the molecule remains protruding from one electrode even after the rupture of the junction, and therefore, the same single-molecule junction can be reestablished if the electrodes are closed again. In the room-temperature measurements, however, weak opening-closing correlations are found, indicating a significant rearrangement of the junction after the rupture and the related loss of structural memory effects.
我们研究了单分子纳米线对结的临时断开的脆弱性。为此，我们比较了金-4,4'-联吡啶-金单分子纳米线在打开和关闭过程中室温及低温下的结形成轨迹。在低温测量中，打开和随后关闭电导迹线之间的互相关性显示出强烈的结构记忆效应：大约一半的分子打开迹线在结再次关闭时呈现出相似的、统计相关的分子特征。这意味着即使结破裂后，结仍保持刚性，分子仍从一个电极突出，因此，如果电极再次闭合，相同的单分子结可以重新建立。然而，在室温测量中，发现打开-关闭相关性较弱，表明结在破裂后发生了显著的重新排列，以及相关的结构记忆效应丧失。
