Atom Transfer and Single-Adatom Contacts

Stable single-atom contacts of zinc whiskers

We report low-temperature measurements of the electrical transport properties of single-atom and tunnel contacts of Zn. We present a variant of the mechanically controllable break-junction technique that comprises a whisker as the central part. This technique combines the possibility to fabricate reproducibly single-atom contacts and well-characterized electronic and lattice properties of the e...

Spin-transfer torque on a single magnetic adatom.

We theoretically show how the spin orientation of a single magnetic adatom can be controlled by spin polarized electrons in a scanning tunneling microscope configuration. The underlying physical mechanism is spin assisted inelastic tunneling. By changing the direction of the applied current, the orientation of the magnetic adatom can be completely reversed on a time scale that ranges from a few...

Conduction channels at finite bias in single-atom gold contacts

Stretching single atom contacts at multiple subatomic step-length.

This work describes jump-to-contact STM-break junction experiments leading to novel statistical distribution of last-step length associated with conductance of a single atom contact. Last-step length histograms are observed with up to five for Fe and three for Cu peaks at integral multiples close to 0.075 nm, a subatomic distance. A model is proposed in terms of gliding from a fcc hollow-site t...

Stabilizing single atom contacts by molecular bridge formation.

Gold-molecule-gold junctions can be formed by carefully breaking a gold wire in a solution containing dithiolated molecules. Surprisingly, there is little understanding on the mechanical details of the bridge formation process and specifically on the role that the dithiol molecules play themselves. We propose that alkanedithiol molecules have already formed bridges between the gold electrodes b...