Exchange-interaction effects on the conductance of long quantum wires
The effect of exchange-interaction on the two-terminal conductance of fully ballistic samples is studied using a many-particle wave packet formalism. The approach shows that the puzzling nonuniversal conductance quantization for long quantum wires can be explained as a fermion exchange interaction effect. The Landauer conductance step Go ≡ 2e2/h is obtained when two-electron interaction is considered. Reductions of Go are due to a wave packet many-particle exchange interaction effect. For ballistic GaAs/AlGaAs quantum wires longer than 1 µm, a conductance step reduction is obtained in agreement with experimental results.