We present measurements of current-voltage (I-V) curves on gold quantum point contacts (QPCs) with a conductance up to 4 G(0) (G(0) = 2e(2)/h is the conductance quantum) and voltages up to 2 V. The QPCs are formed between the gold tip of a scanning tunneling microscope and a Au(110) surface under clean ultra-high-vacuum conditions at room temperature. The I - V curves are found to he almost linear in contrast to previous reports. Tight-binding calculations of I - V curves for one- and two-atom contacts are in excellent agreement with our measurements. On the other hand, clearly nonlinear I - V curves are only observed when the sample has been cleaned in air. (C) 2000 American Institute of Physics.
Bibliographical noteCopyright (2000) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
- SCALE METALLIC CONTACTS
- CONDUCTANCE QUANTIZATION