Microscopic mechanisms of dephasing due to electron-electron interactions

(Dated: February 2, 2008)We develop a non-perturbative numerical method to study tunneling of a single electron throughan Aharonov-Bohm ring where several strongly interacting electrons are bound. Inelastic pro-cesses and spin-flip scattering are taken into account. The method is applied to study microscopicmechanisms of dephasing in a non-trivial model. We show that electron-electron interactions de-scribed by the Hubbard Hamiltonian lead to strong dephasing: the transmission probability at fluxΦ = π is high even at small interaction strength. In addition to inelastic scattering, we identifytwo energy conserving mechanisms of dephasing: symmetry-changing and spin-flip scattering. Themany-electron state on the ring determines which of these mechanisms will be at play: transmittedcurrent can occur either in elastic or inelastic channels, with or without changing the spin of thescattering electron.