@article{discovery141512, publisher = {AMERICAN PHYSICAL SOC}, month = {May}, volume = {98}, year = {2007}, title = {Formation of a metallic contact: Jump to contact revisited}, journal = {PHYS REV LETT}, number = {20}, note = {{\copyright} 2007 The American Physical Society}, issn = {0031-9007}, keywords = {SINGLE-ATOM CONTACT, TRANSITION-METALS, ADHESION, CONDUCTANCE, MECHANISMS, SIGNATURE, TIP}, author = {Untiedt, C and Caturla, MJ and Calvo, MR and Palacios, JJ and Segers, RC and Van Ruitenbeek, JM}, url = {http://dx.doi.org/10.1103/PhysRevLett.98.206801}, abstract = {The transition from tunneling to metallic contact between two surfaces does not always involve a jump, but can be smooth. We have observed that the configuration and material composition of the electrodes before contact largely determine the presence or absence of a jump. Moreover, when jumps are found preferential values of conductance have been identified. Through a combination of experiments, molecular dynamics, and first-principles transport calculations these conductance values are identified with atomic contacts of either monomers, dimers, or double-bond contacts.} }