Many-electron scattering applied to atomic point contacts

Electron transport in a strong coupling regime is investigated by applying the many-electron correlated scattering (MECS) method to an atomic point contact model. Comparing the theoretical calculations to the quantum of conductance obtained experimentally for these systems allows for the error associated with the numerical implementation of the MECS method to be estimated and attributed to different components of the calculations. Errors associated with implementing the scattering boundary conditions and determination of the applied voltage in a finite explicit electrode model are assessed, and as well the impact on the basis set description on predicting the conductance is examined in this weakly correlated limit. The MECS calculation for the atomic point contact results in a conductance of 0.6G(0), in reasonable agreement with measurements for gold point contacts where approximately the conductance quantum G(0) is obtained. The analysis indicates the error attributable to numerical approximations and the explicit electrode model introduced in the calculations should not exceed 40% of the total conductance, whereas the effect of electron-electron correlations, even in this weakly correlated regime, can result in as much as a 30% change in the predicted conductance.