Electrical and thermoelectrical transport in Dirac fermions through a quantum dot

Understand

We investigate the conductance and thermopower of massless Dirac fermions through a quantum dot using a pseudogap Anderson model in the non-crossing approximation.

• When the Fermi level is at the Dirac point, the conductance has a cusp where the thermopower changes its sign.
• When the Fermi level is away from the Dirac point, the Kondo temperature illustrates a quantum impurity transition between an asymmetric strong coupling Kondo state and a localized moment state.
• The conductance shows a peak near this transition and reaches the unitary limit at low temperatures.