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Controlling the dynamics of a single atom in lateral atom manipulation
Joseph A Stroscio1, Robert J Celotta
1Electron Physics Group, National Institute of Standards and Technology, Gaithersburg, MD 20899-8412, USA. joseph.stroscio@nist.gov
Science (New York, N.Y.)
|September 11, 2004
Summary
We observed a single cobalt atom switching between surface sites on copper. Tip height and voltage influenced atom movement, revealing insights into atom manipulation and surface dynamics.
Area of Science:
- Surface science
- Atomic manipulation
- Scanning tunneling microscopy
Background:
- Understanding atom dynamics on surfaces is crucial for nanoscale engineering.
- Low-temperature scanning tunneling microscopy (LT-STM) enables atomic-level surface studies.
Purpose of the Study:
- To investigate the dynamics of a single cobalt (Co) atom during lateral manipulation on a copper (111) surface.
- To reveal Co binding site locations and atom motion within the scanning tip's trapping potential.
Main Methods:
- Utilized a low-temperature scanning tunneling microscope (LT-STM) for atomic manipulation.
- Analyzed random telegraph noise to identify transitions between hexagonal close-packed (hcp) and face-centered cubic (fcc) sites.
- Varied probe tip height and tunneling voltage to study their effects on atom dynamics.
Main Results:
- Detailed imaging revealed Co atom motion within the tip's trapping potential.
- Observed random telegraph noise indicating Co atom switching between hcp and fcc sites.
- Demonstrated that tip height modifies the surface potential, affecting residence times.
- Identified distinct behaviors at low (<5 meV) and high tunneling voltages, with the latter showing dependence on voltage, suggesting vibrational heating.
Conclusions:
- The study elucidates the dynamic behavior of single Co atoms on Cu(111) surfaces.
- Lateral manipulation with an STM tip can induce site switching, influenced by surface potential and tip parameters.
- Vibrational heating via inelastic electron scattering plays a role at higher tunneling voltages, impacting atom transfer rates.
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