Jasper-Tönnies Torben, Garcia-Lekue Aran, Frederiksen Thomas, Ulrich Sandra, Herges Rainer, Berndt Richard
Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany.
Donostia International Physics Center, DIPC, Paseo Manuel de Lardizabal 4, E-20018 Donostia-San Sebastián, Spain.
Phys Rev Lett. 2017 Aug 11;119(6):066801. doi: 10.1103/PhysRevLett.119.066801. Epub 2017 Aug 7.
A freestanding molecular wire is placed vertically on Au(111) using a platform molecule and contacted by a scanning tunneling microscope. Despite the simplicity of the single-molecule junction, its conductance G reproducibly varies in a complex manner with the electrode separation. Transport calculations show that G is controlled by a deformation of the molecule, a symmetry mismatch between the tip and molecule orbitals, and the breaking of a C≡C triple in favor of a Au─C─C bond. This tip-controlled reversible bond formation or rupture alters the electronic spectrum of the junction and the states accessible for transport, resulting in an order of magnitude variation of the conductance.
使用一个平台分子将一根独立的分子线垂直放置在Au(111)上，并通过扫描隧道显微镜进行接触。尽管单分子结结构简单，但其电导G会随着电极间距以复杂的方式反复变化。输运计算表明，G受分子变形、针尖与分子轨道之间的对称性失配以及有利于Au─C─C键的C≡C三键断裂的控制。这种由针尖控制的可逆键形成或断裂改变了结的电子光谱以及可用于输运的状态，导致电导发生一个数量级的变化。
