Quantum Conductance Oscillations in Metal/Molecule/Metal Switches at Room Temperature

TL;DR

This study demonstrates room-temperature quantum conductance oscillations in metal/molecule/metal switches, revealing nanoscale pathways and interference effects that suggest potential atomic-scale switching applications.

Contribution

It provides experimental evidence of quantum conductance oscillations and interference effects in molecular junctions at room temperature, advancing understanding of nanoscale switching mechanisms.

Findings

Pressure-induced conductance peaks <30 nm indicate nanoscale pathways.

Oscillations and dips in conductance suggest quantum interference effects.

Results support potential use as atomic-scale switches.

Abstract

Conductance switching has been reported in many molecular junction devices, but in most cases has not been convincingly explained. We investigate conductance switching in Pt/stearic acid monolayer/Ti devices using pressure-modulated conductance microscopy. For devices with conductance G>>G_Q or G<<G_Q, where GQ=2e^2/h is the conductance quantum, pressure-induced conductance peaks <30 nm in diameter are observed, indicating the formation of nanoscale conducting pathways between the electrodes. For devices with G~ 1- 2 G_Q, in addition to conductance peaks we also observed conductance dips and oscillations in response to localized pressure. These results can be modeled by considering interfering electron waves along a quantum conductance channel between two partially transmitting electrode surfaces. Our findings underscore the possible use of these devices as atomic-scale switches.