Bistable hysteresis and resistance switching in hydrogen gold junctions

TL;DR

This paper investigates hysteresis and resistance switching in hydrogen-gold molecular junctions, revealing vibrational heating effects and demonstrating the potential for long-lasting, switchable nanoscale devices.

Contribution

It uncovers the link between hysteresis and vibrational heating in H2-Au junctions and shows how to engineer junctions with hysteresis times exceeding days.

Findings

Hysteresis is connected to vibrational heating effects.

Hysteresis time scales linearly with dissipated power.

Long-term stable switchable devices are achievable.

Abstract

Current-voltage characteristics of H2-Au molecular junctions exhibit intriguing steps around a characteristic voltage of 40 mV. Surprisingly, we find that a hysteresis is connected to these steps with a typical time scale > 10 ms. This time constant scales linearly with the power dissipated in the junction beyond an ofset power P_s = IV_s. We propose that the hysteresis is related to vibrational heating of both the molecule in the junction and a set of surrounding hydrogen molecules. Remarkably, we can engineer our junctions such that the hysteresis' characteristic time becomes >days. We demonstrate that reliable switchable devices can be built from such junctions.