Electronic thermal conductivity of disordered metals

We calculate the thermal conductivity of interacting electrons in disordered metals. In our analysis we point out that the interaction affects thermal transport through two distinct mechanisms, associated with quantum interference corrections and energy exchange of the quasiparticles with the electromagnetic environment, respectively. The latter is seen to lead to a violation of the Wiedemann-Franz law. Our theory, valid to all orders in perturbation theory, predicts a strong enhancement of the Lorenz ratio κ∕σT over the value predicted by the Wiedemann-Franz law, when the electrons encounter a large environmental impedance.