Conductance and Thermopower of Dirac Fermions under the Kondo Effect

We investigate the conductance, thermopower of Dirac fermions through a quantum dot via tunneling barriers described by a pseudogap Anderson model. A sharp peak of the conductance appears when the impurity moment changes abruptly, indicating an impurity quantum phase transition between the Kondo and local moment regimes. In the Kondo regime, the conductance increases as the temperature decreases. The thermopower changes its sign near the Kondo temperature. The Kondo behavior of the pseudogap model is similar to the conventional Kondo problem.