Tip-induced bond weakening, tilting, and hopping of a single CO molecule on Cu(100)  

作　　者：Xiaoru Dong Ben Yang Rui Zhu Ruipu Wang Yang Zhang Yao Zhang Zhenchao Dong 

机构地区：[1]Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Centre of Quantum information and Quantum Physics,University of Science and Technology of China,Hefei,China

出　　处：《Light(Advanced Manufacturing)》2022年第4期103-112,共10页光（先进制造）（英文）

基　　金：supported by the National Key R&D Program of China(Grant Nos.2021YFA1500500 and 2016YFA0200600);National Natural Science Foundation of China(Grant No.21790352);Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB36000000);the Anhui Initiative in Quantum Information Technologies(Grant No.AHY090000);support from the China National Postdoctoral Program for Innovative Talents(No.BX2021282).

摘　　要：The interaction between a probing tip and an adsorbed molecule can significantly impact the molecular chemical structure and even induce its motion on the surface.In this study,the tip-induced bond weakening,tilting,and hopping processes of a single molecule were investigated by sub-nanometre resolved tip-enhanced Raman spectroscopy(TERS).We used single carbon monoxide(CO)molecules adsorbed on the Cu(100)surface as a model system for the investigation.The vibrational frequency of the C−O stretching mode is always redshifted as the tip approaches,revealing the weakening of the C−O bond owing to tip−molecule interactions.Further analyses of both the vibrational Stark effect and TERS imaging patterns suggest a delicate tilting phenomenon of the adsorbed CO molecule on Cu(100),which eventually leads to lateral hopping of the molecule.While a tilting orientation is found toward the hollow site along the[110]direction of the Cu(100)surface,the hopping event is more likely to proceed via the bridge site to the nearest Cu neighbour along the[100]or[010]direction.Our results provide deep insights into the microscopic mechanisms of tip−molecule interactions and tip-induced molecular motions on surfaces at the single-bond level.

关 键 词：Scanning tunneling microscope TERS CO molecule Vibration Pauli repulsion Stark effect Tip−molecule interaction 

分 类 号：O64[理学—物理化学]