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- Okuyama, H, et al.
(författare)
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Modifying current-voltage characteristics of a single molecule junction by isotope substitution : OHOD dimer on Cu(110)
- 2012
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 85:20
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Tidskriftsartikel (refereegranskat)abstract
- Vibrationally induced configurational change and nonlinear current-voltage (I-V) characteristics are investigated within the scanning tunneling microscope (STM) junction, including hydroxyl dimers on a Cu(110) surface. H-bonded hydroxyl dimers composed of OH and/or OD have a unique inclined geometry that can be switched back and forth by vibrational excitations via the inelastic electron tunneling process of the STM. The relative occupation change between the high-and low-conductance states as a function of bias voltage critically depends on the isotopic compositions, and thus the I-V characteristics can be modified to exhibit negative differential resistance by H/D substitution. The experimental results of the occupation change and I-V curves are nicely reproduced using a recently proposed analytical model combined with comprehensive density functional calculations for the input parameters (vibrational modes and their emission rates by tunneling electrons, conductance, and relative occupation change of high-and low-conductance states), and they underlines the different roles played by the free and shared O-H(D) stretch modes of the hydroxyl dimers on a Cu(110) surface.
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