On the formation of suspended double-stranded atomic chains

The smallest structures with higher stability connecting two metallic electrodes can be identified by the evolution of the conductance in the process of the controlled breakage of the contact between two metals. Here we report on the identification of double-stranded atomic chains formed on Au using a Scanning Tunneling Microscope. Molecular dynamics simulations and density functional theory electron transport calculations help to unveil the richness of geometric structures possible with double-stranded chains, their stability and how these can evolve to form monoatomic chains.