We study a single-channel one-dimensional Kondo model where the impurity spin is replaced by an SU($N$) spin. Using Abelian bosonization and canonical transformation we explicitly show that this system has an exactly solvable point. The calculation also shows that there are $n$ collective excitation modes in the system, one charged and $n-1$ neutral spin excitation modes.

• Received 5 November 2010

DOI:https://doi.org/10.1103/PhysRevB.83.134423