Electronic effects in the length distribution of atom chains
J N Crain1, M D Stiles, J A Stroscio
1Electron Physics Group, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8412, USA.
Physical Review Letters
|May 23, 2006
Summary
Self-assembled gold atomic chains on Si(553) form finite segments due to defects. Oscillations in chain length distribution suggest changes in cohesive energy, linked to electronic scattering at the Fermi surface.
Area of Science:
- Surface science
- Condensed matter physics
- Materials science
Background:
- Gold deposition on silicon surfaces can induce self-assembly of atomic structures.
- Surface defects play a crucial role in segmenting and influencing these self-assembled chains.
- Understanding atomic chain formation is key to novel electronic and catalytic applications.
Purpose of the Study:
- To investigate the self-assembly of gold atomic chains on the Si(553) surface.
- To analyze the distribution of chain lengths and the impact of defects.
- To explore the correlation between defects and chain coupling.
Main Methods:
- Utilized scanning tunneling microscopy (STM) for high-resolution surface imaging.
- Analyzed the spatial distribution of defects and atomic chain segments.
- Calculated pairwise correlation functions to determine defect interactions.
Main Results:
- Observed self-assembled gold atomic chains on Si(553) broken into finite segments by defects.
- Identified oscillations in chain length distribution, indicating length-dependent cohesive energy.
- Detected long-range correlations between defects, suggesting inter-chain coupling.
Conclusions:
- The cohesive energy of gold atomic chains on Si(553) exhibits oscillations with chain length.
- Electronic scattering at the Fermi surface of surface states provides a plausible explanation for these oscillations.
- Defects are coupled over long ranges, influencing the overall structure of the self-assembled system.
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