Mechanically-controllable single molecule switch based on configuration specific electrical conductivity of metal–molecule–metal junctions

Abstract

We report the systematic characterization of configuration-specific electrical conductivity in metal–molecule–metal structures for a demonstration of mechanically controllable contact effect single-molecule switches. Break junction measurements reveal two distinct conductance states of G_H ∼ 1.3 mG₀ and G_L ∼ 0.4 mG₀ in an Au–hexanedithiol–Au system. We provide evidence that transitions from G_H to G_L involve atom scale deformations between two distinct metal–molecule contact configurations by conducting single molecule inelastic electron tunneling spectroscopy. We also examine mechanically controlled binary switching via bistable conductance states, thereby attaining an alkanedithiol single-molecule switch.