Current-induced embrittlement of atomic wires

Recent experiments suggest that gold single-atom contacts and atomic chains break at applied voltages of 1 to 2 V. In order to understand why current flow affects these defect-free conductors, we have calculated the current-i nduced forces on atoms in a Au chain between two Au electrodes. These force s are not by themselves sufficient to rupture the chain. However, the curre nt reduces the work to break the chain, which results in a dramatic increas e in the probability of thermally activated spontaneous fracture of the cha in. This current-induced embrittlement poses a fundamental limit to the cur rent-carrying capacity of atomic wires.