Néel N, Kröger J, Limot L, Frederiksen T, Brandbyge M, Berndt R
Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, D-24098 Kiel, Germany.
Phys Rev Lett. 2007 Feb 9;98(6):065502. doi: 10.1103/PhysRevLett.98.065502. Epub 2007 Feb 7.
The tip of a low-temperature scanning tunneling microscope is approached towards a C60 molecule adsorbed at a pentagon-hexagon bond on Cu(100) to form a tip-molecule contact. The conductance rapidly increases to approximately 0.25 conductance quanta in the transition region from tunneling to contact. Ab-initio calculations within density functional theory and nonequilibrium Green's function techniques explain the experimental data in terms of the conductance of an essentially undeformed C60. The conductance in the transition region is affected by structural fluctuations which modulate the tip-molecule distance.
将低温扫描隧道显微镜的针尖靠近吸附在Cu(100)上五边形-六边形键处的C60分子，以形成针尖-分子接触。在从隧穿到接触的过渡区域，电导迅速增加到约0.25个电导量子。基于密度泛函理论和非平衡格林函数技术的从头算计算，根据基本未变形的C60的电导来解释实验数据。过渡区域的电导受结构涨落影响，结构涨落会调节针尖-分子间距。
