Integer particle preference during charge transfer in Kohn-Sham theory

We investigate the static and dynamic charge transfer that is triggered by external electric fields in model molecular wires. A self-interaction correction in Kohn-Sham density functional theory leads to the desired integer electron transfers that do not occur with standard functionals which miss Coulomb blockade effects. Analysis of the multiplicative exchange-correlation potential in stationary cases and during real-time propagation shows how the local exchange-correlation potential builds up step and reverse-step structures that enforce the integer particle preference. The role of spin-symmetry breaking is discussed.