CO dynamics induced by tunneling electrons: differences on Cu(110) and Ag(110)
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The electronic current originating in a scanning tunneling microscope (STM) can be used to induce motion and desorption of adsorbates on surfaces. The manipulation of CO molecules on noble metal surfaces is an academic case that has received little theoretical attention. Here, we do thorough density functional theory calculations that explore the chemisorption of CO on Cu(110) and Ag(110) surface and its vibrational properties. The STM induced dynamics are explored after excitation of the highest lying mode, the C–O stretch. In order to give a complete account of this dynamics, the lifetime of the different CO modes is evaluated (by only including the mode decay into electronic excitations of the host surface) as well as the intermode coupling. Hence, after excitation of the stretch mode, the lower-energy modes are populated via intermode coupling and depopulated by electron-hole excitations. This study reveals the intrinsic features of the STM induced motion of CO on Cu(110) and Ag(110).
KeywordsDensity Functional Theory Chemisorption Noble Metal Scanning Tunneling Microscope Mode Decay
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- G. Dujardin, R.E. Walkup, Ph. Avouris, Science 255, 1232 (1992); B.C. Stipe, M.A. Rezaei, W. Ho, S. Gao, M. Persson, B.I. Lundqvist, Phys. Rev. Lett. 78, 4410 (1997) Google Scholar
- B.J. McIntyre, M. Salmeron, G.A. Somorjai, Science 265, 1415 (1994) Google Scholar
- B.N.J. Persson, H. Ueba, Surf. Sci. 502/503, 18 (2002) Google Scholar
- L.J. Lauhon, W. Ho, Phys. Rev. B 60, R8525 (1999) Google Scholar
- J.I. Pascual, N. Lorente, in SPM beyond imaging, edited by P. Samori (Wiley-VHC, Berlin, 2005) Google Scholar
- N. Lorente, R. Rurali, H. Tang, J. Phys.: Condens. Matter 17, S1049 (2005) Google Scholar
- Dacapo is freely downloadable from: http://www.fysik.dtu.dk/campos/ASE/ Google Scholar
- It is interesting to note that the Cu(110) surface phonons are harder than the Ag(110) one, indicating a stronger Cu–Cu interaction than in the Ag case, because the mass difference does not account for the phonon top of band distance (21 meV for the longitudinal modes of Cu against 13.7 meV of Ag(110) ) Google Scholar
- U. Burghaus, H. Conrad, Surf. Sci. 338, L869 (1995) Google Scholar
- C. Blyholder, J. Phys. Chem. 68, 2772 (1964) Google Scholar
- R.A. Pelak, W. Ho, Surf. Sci. 321, L233 (1994) Google Scholar