Origin of Symmetric Dimer Images of Si(001) Observed by Low-Temperature Scanning Tunneling Microscopy
- Title
- Origin of Symmetric Dimer Images of Si(001) Observed by Low-Temperature Scanning Tunneling Microscopy
- Author
- 조준형
- Keywords
- MINIMUM ENERGY PATHS; ELASTIC BAND METHOD; BUCKLED DIMERS; SADDLE-POINTS; SURFACE; SILICON; RECONSTRUCTION; SI(100); SPECTROSCOPY; TRANSITION
- Issue Date
- 2016-06
- Publisher
- NATURE PUBLISHING GROUP
- Citation
- SCIENTIFIC REPORTS, v. 6, Page. 1-7
- Abstract
- It has been a long-standing puzzle why buckled dimers of the Si(001) surface appeared symmetric below similar to 20 K in scanning tunneling microscopy (STM) experiments. Although such symmetric dimer images were concluded to be due to an artifact induced by STM measurements, its underlying mechanism is still veiled. Here, we demonstrate, based on a first-principles density-functional theory calculation, that the symmetric dimer images are originated from the flip-flop motion of buckled dimers, driven by quantum tunneling (QT). It is revealed that at low temperature the tunneling-induced surface charging with holes reduces the energy barrier for the flipping of buckled dimers, thereby giving rise to a sizable QT-driven frequency of the flip-flop motion. However, such a QT phenomenon becomes marginal in the tunneling-induced surface charging with electrons. Our findings provide an explanation for low-temperature STM data that exhibits apparent symmetric (buckled) dimer structure in the filled-state (empty-state) images.
- URI
- https://www.nature.com/articles/srep27868https://repository.hanyang.ac.kr/handle/20.500.11754/72415
- ISSN
- 2045-2322
- DOI
- 10.1038/srep27868
- Appears in Collections:
- COLLEGE OF NATURAL SCIENCES[S](자연과학대학) > PHYSICS(물리학과) > Articles
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- Origin of Symmetric Dimer Images of Si(001) Observed by Low-Temperature Scanning Tunneling Microscopy.pdfDownload
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