An experimental set-up to probe the quantum transport through a single atomic$$/$$molecular junction at room temperature

Abstract

Understanding the transport characteristics at the atomic limit is the prerequisite for futuristic nanoelectronic applications. Among various experimental procedures, mechanically controllable break junction (MCBJ) is a well-adopted experimental technique to study and control atomic or molecular scale devices. Here, we present the details of developing a piezo-controlled table-top MCBJ set-up, working at ambient conditions, along with the necessary data acquisition technique and analysis of the data. We performed the conductance experiment on a macroscopic gold wire, which exhibits a quantised conductance plateau upon pulling the wire. Conductance peak up to ~ 20G0 (G0 = 2e2\(/\)h where e is the electronic charge and h is the Planck’s constant) could be resolved at room temperature. A well-known test bed molecule, 4,4′-bipyridine, was introduced between the gold electrodes and the conductance histogram exhibits two distinctive conductance peaks, confirming the formation of a single molecular junction, in line with the previous reports. This demonstrates that our custom-designed MCBJ set-up can measure the quantum transport of a single molecular junction at ambient conditions.