Quantized Conductance of Au Break Junctions:
by Laetitia Soukiassian.
We have built a simple apparatus based on a piezoelectric tube that permits a repetitive formation and breakage of these junctions.
By applying a constant voltage of ~25 mV, a current is made to flow through the junction. Using a digital oscilloscope and a homemade
I-V converter the current is measured as a function of time as the junction is broken. Measurements made at room temperature reveal
steps in the current. The oscilloscope is interfaced with a computer in order to perform a statistical analysis of the current features.
Our data will be presented and analyzed in terms of the Landauer formalism for current flow through small constrictions.
The features of the conductance histograms we have measured are consistent with the quantization of the conductance in units
Last modified: Fri Jul 19 11:06:33 EST 2002