Numerical renormalization-group results on entropy of the anisotropic two-channel Kondo model with the band-width cutoff ($D$) in the presence of a magnetic field ($h$) are obtained to determine crossover temperature from the non-Fermi liquid to Fermi liquid fixed point. It is found that the crossover temperature ($T_{ \rm x}$) is given by $T_{ \rm x} \equiv { r} T_{ \rm K} \sim D(\Delta J/J_{ \rm av})^2 e^{ -1/J_{ \rm av}}$ when $(h /T_{ \rm K})^2 \ll r \ll 1 $, where $T_{ \rm K}$, $J_{ \rm av}$ and $\Delta J$ are the Kondo temperature, the average and difference of the exchange coupling constants, respectively. This result indicates that non-Fermi liquid behavior can be seen even if $\Delta J > T_{ \rm K}$. Robust similarities of the crossover behavior in the region around the non-Fermi liquid critical point to that of the two-impurity Kondo model are also discussed.
Categories: cond-mat