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Published on: May 15, 2017
Sn/Ge(111) surface charge-density-wave phase transition
1Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801-3080 and and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, 104 South Goodwi.
Physical Review Letters
|October 13, 2000
Summary
Surface electronic structure of tin on germanium(111) reveals a gap opening in the low-temperature phase. This unusual Peierls-like transition is driven by surface defects, not Fermi nesting.
Area of Science:
- Surface Science
- Condensed Matter Physics
- Materials Science
Background:
- The surface electronic structure of tin (Sn) on germanium (Ge)(111) exhibits distinct phases.
- Understanding these phases is crucial for developing novel electronic materials.
Purpose of the Study:
- To investigate the surface electronic structure of 1/3 monolayer Sn on Ge(111) in its room-temperature and low-temperature phases.
- To elucidate the mechanism behind the observed electronic behavior, particularly the gap opening.
Main Methods:
- Angle-resolved photoemission spectroscopy (ARPES) was employed to probe the electronic states.
- Theoretical calculations were performed to understand the symmetry and electronic response.
Main Results:
- A significant electronic band gap opens around the (3x3) Brillouin zone boundary in the low-temperature phase.
- This gap formation suggests a Peierls-like transition, occurring despite the absence of Fermi surface nesting.
- The electronic behavior is highly sensitive to doping from intrinsic surface defects.
Conclusions:
- Intrinsic surface defects play a critical role in driving the Peierls-like transition and the observed (3x3) symmetry.
- The findings challenge conventional understanding of Peierls transitions in similar systems.
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