Electronic Conductance of Platinum Atomic Contact in a Nitrogen Atmosphere

We have investigated the platinum atomic contact in a nitrogen atmosphere using mechanically controllable break junction technique and theoretical calculation. Conductance, dI/dV measurement, and theoretical calculation revealed a single N2 molecule placed between platinum electrodes, where the N2 molecular axis was parallel to the junction axis. The conductance of the single N2 molecular junction was 1 G0 (=2e2/h), which was comparable to that of metal atomic contacts indicating the strong interaction between the nitrogen molecule and Pt electrodes. Theoretical calculation supported the high conductivity of the molecular junction and revealed that two dominant channels contributed to the electron transport through the junction. The two dominant channels were from the coupling between orbitals (dxz and dyz) of Pt atom and orbitals (px and py) of N atom.