Nonlinear effects in conductance histograms of atomic-scale metallic contacts

General properties of conductance histograms of atomic-scale metallic conta cts are discussed. Nonlinear effects are included assuming a quasiadiabatic representation for electron transport. Histograms of conductance and histo grams of differential conductance markedly differ when increasing the bias voltage. Averaging over different nanowire breakage paths at high bias rapi dly smears out the peaks in IIV histograms, while it leads to new peaks at half integer values in dI/dV histograms. Recent experimental results on the histograms evolution with the applied bias are discussed.