Abstract
We have devised a “square micro-four-point probe method” using an independently driven ultrahigh-vacuum four-tip scanning tunneling microscope, and succeeded for the first time to directly measure anisotropic electrical conductance of a single-atomic layer on a solid surface. A quasi-one-dimensional metal of a single-domain had a surface-state conductance along the metallic atom chains () to be at room temperature, which was larger than that in the perpendicular direction () by times. The was consistently interpreted by a Boltzmann equation with the anisotropic surface-state band dispersion, while the was dominated by a surface-space-charge-layer conductance.
- Received 4 April 2003
DOI:https://doi.org/10.1103/PhysRevLett.91.036805
©2003 American Physical Society