Conductance and Its Bias Dependence in Hard and Soft Metallic Nanocontacts
Abstract
Conductance of breaking point contacts in relays and its bias dependence have been measured for hard (Rh) and soft (In) contact materials. When the Rh contact is broken, some transient conductance traces show conductance plateaus near the conductance quantum G_0=2e^2/h. However, these plateaus appear so rarely that the conductance histogram shows no peaks at 1G_0, but a broad peak at around 1.4G_0. This peak shifts to 2G0 and decreases in height when the bias voltage Vb increases to 500 mV. The In histogram shows a pronounced peak at around 1.3G_0, which also decreases with increasing Vb and disappears at around 2 V. It is interesting that the non-integer conductance peak of In has the same bias dependence as that of the 1G0 peak of Au which also disappears at 1.9 V (H. Yasuda and A. Sakai, Phys. Rev. B56, 1069 (1997)). This result suggests that the suppression of the conductance peak, or the stability of the quantum point contact under high biases, is not related to whether the conductance takes the quantized value or not.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1998
- Bibcode:
- 1998APS..MAR.Q3210S