Magnetic impurity in a luttinger liquid: A view from conformal field theory

Abstract

Exact results are reported for the low-temperature thermodynamics of a spin-1/2 magnetic impurity coupled to a 1D interacting electron system. The use of conformal field theory techniques reveals that there are only two types of critical behaviors consistent with the symmetries of the problem: either a local Fermi liquid, or else a theory identical to that recently proposed by Furusaki and Nagaosa. We also show that forward electron scattering on the impurity produces the same critical behavior as the two-channel Kondo effect for noninteracting electrons.