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The atomic force microscope (AFM) is a fascinating tool that enables us to explore the forces and phenomenology associated with the formation of a single bond between the foremost front atom of a sharp probe and individual atoms at surfaces [1,2]. This phenomenology includes the dissipation of energy from the cantilever oscillation; an observable that produces images with atomic-scale contrast [3], and it is closely related to friction and adhesion. In this contribution, we will present a combination of force spectroscopic measurements and first-principles calculations that has contributed in a decisive way to further clarify the enhancement of atomic contrast in the signal associated with the energy dissipated from the cantilever oscillation [4]. We will also discuss implications of these results regarding signatures of energy dissipation in the behavior of AFM observables that, a priori, should only reflect the conservative part of the tip-surface interaction [5,6], and that have been recently identified in vertical atomic manipulation experiments [7].
References: [1] M. A. Lantz, et al., Science 291, 2580 (2001) [2] Y. Sugimoto, et al., Nature 445, 64 (2007) [3] R. Bennewitz, et al., Phys. Rev. B 62, 2074 (2000) [4] N. Oyabu, et al., Phys. Rev. Lett. 96, 106101 (2006) [5] A. Schirmeisen et al., Phys. Rev. Lett. 97, 136101 (2006) [6] H. Hölscher, et al., Phys. Rev. B 64, 075402 (2001) [7] Y. Sugimoto, et al., Science 322, 413 (2008) |
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