Mechanical Properties of Metallic One-Atom Quantum Point Contacts
It is possible to fabricate nanoscopic metallic structures moving the atoms one by one with a scanning tunneling microscope. This technique can be combined with atomic force microscopy, allowing for a combined study of the electronic transport and the mechanical behaviour during the fabrication of these nanoscopic structures. Our experiments show that there is a close relationship between conductance and applied force during the formation of one-atom quantum point contacts. It is shown taht the mechanical process of stretching an atomicsized metallic contact proceeds in a discrete sequence of structural transformations involving elastic and yielding stages.
We have also found that it is possible to obtain a chain of several single gold atoms from a one-atom contact of gold . This new structure is a truly onedimensional conductor and the conductance is independent of its length and has the same value as a single one-atom contact of gold : one conductance quantum (2e2/h).
KeywordsMechanical Property Dynamical System State Physics Atomic Force Microscopy Electronic Transport