A Model for Two-Channel Kondo Effect in CNT Quantum Dot

Over-screened Kondo effect is feasible in carbon nanotube quantum dot junction hosting a spin $\frac{1}{2}$ atom with single $s$-wave valence electron (e.g Au). The idea is to use the two valleys as two symmetry protected flavor quantum numbers $\xi =\mathbf{K},{\mathbf{K}}^{\mathrm{\prime }}$. Perturbative RG analysis exposes the finite weak-coupling two-channel fixed point, where the Kondo temperature is estimated to be around $0.5÷5$~K. Remarkably, occurrence of two different scaling regimes implies a non-monotonic dependence of the conductance as function of temperature.