Condensed Matter Seminar Series

Title: Coherent and Dissipative Transport in Metallic Atomic-size Contacts

Alexei Marchenkov

Georgia Tech

Thursday March 29,  11:30 am,  Room 298,  Physics Building

Abstract:  Comprehensive measurements of transport properties of  nanoscale metallic contacts may provide sufficient information to  deduce their atomic structure. I will demonstrate completely  reversible mechanical manipulation of the electronic state of atomic- size niobium contacts. This ubiquitous "elastic" regime includes  switching between two distinct configurations, which occurs via  random telegraph noise. Based on synergetic first-principles  numerical modeling of the structure and transport properties, we have  concluded that the smallest contacts are formed by Nb2 dimers trapped  between apexes of bulk leads. I will discuss the effect of the  dimer's vibrational degrees of freedom on the charge transport across  the junction, including the onset of dissipation within the contact.