Tuesday, July 30, 2013

1307.7550 (Yulia E. Shchadilova et al.)

Rotation of a single acetylene molecule on Cu(001) by tunneling
electrons in STM

Yulia E. Shchadilova, Sergei G. Tikhodeev, Magnus Paulsson, Hiromu Ueba
We study the elementary processes behind one of the pioneering works on STM controlled reactions of single molecules [Stipe et al., Phys. Rev. Lett. 81, 1263 (1998)]. Using the Keldysh-Green function approach for the vibrational generation rate in combination with DFT calculations to obtain realistic parameters we reproduce the experimental rotation rate of an acetylene molecule on a Cu(100) surface as a function of bias voltage and tunneling current. This combined approach allows us to identify the reaction coordinate mode of the acetylene rotation and its anharmonic coupling with the C-H stretch mode. We show that three different elementary processes, the excitation of C-H stretch, the overtone ladder climbing of the hindered rotational mode, and the combination band excitation together explain the rotation of the acetylene molecule on Cu(100).
View original: http://arxiv.org/abs/1307.7550

No comments:

Post a Comment