Electrode geometry influencing the tunnel resistance in a mechanically controllable break junction

✍ Scribed by R.J.P. Keijsers; J. Voets; O.I. Shklyarevskii; H. van Kempen

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 307 KB
• Volume: 218
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(95)00615-x

✦ Synopsis

In the conventional tunneling picture, the dependence of the tunnel resistance on the distance between two electrodes in vacuum is expected to be exponential. We have observed, however, clear deviations from this behavior over four to six orders of magnitude of the tunnel resistance at constant biases of 5-100 mV, using highly stable mechanically controllable break junctions of AI, Ag, Au, Pt, and PtIr. Previous theoretical studies indicate that deviations from exponential behavior can be caused by interactions between the two electrodes, as well as by certain electrode geometries. Since the first are predicted to influence the tunnel resistance over at most two orders of magnitude in the region close to contact, whereas the latter may extend over more than four orders of magnitude, we believe to have observed effects due to several different types of geometries.