Paper SP+2D+AS+EM+MC+NS+SS-ThM5
Conductivity of Si(111) - 7 × 7: The Role of a Single Atomic Step
Thursday, November 13, 2014, 9:20 am, Room 312
| Session: |
Probing Electronic and Transport Properties |
| Presenter: |
Robert Wolkow, University of Alberta and The National Institute for Nanotechnology, Canada |
| Authors: |
B. Martins, University of Alberta and The National Institute for Nanotechnology, Canada
M. Smeu, McGill University, Canada
H. Guo, McGill University, Canada
R. Wolkow, University of Alberta and The National Institute for Nanotechnology, Canada
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| Correspondent: |
Click to Email |
The Si(111) - 7 × 7 surface is one of the most interesting semiconductor surfaces because of its
complex reconstruction and fascinating electronic properties. While it is known that the Si - 7 × 7 is
a conducting surface, the exact surface conductivity has eluded consensus for decades as measured
values differ by 7 orders of magnitude. Here we report a combined STM and transport measurement
with ultra-high spatial resolution and minimal interaction with the sample, and quantitatively determine the intrinsic conductivity of the Si - 7 × 7 surface. This is made possible by the capability of
measuring transport properties with or without a single atomic step between the measuring probes:
we found that even a single step can reduce the surface conductivity by two orders of magnitude.
Our first principles quantum transport calculations confirm and lend insight to the experimental
observation.