Conformal-field-theory approach to the two-impurity Kondo problem: Comparison with numerical renormalization-group results

Ian Affleck, Andreas W. W. Ludwig, Barbara A. Jones
1995 Physical Review B (Condensed Matter)  
Numerical renormalization group and conformal field theory work indicate that the two impurity Kondo Hamiltonian has a non-Fermi liquid critical point separating the Kondo-screening phase from the inter-impurity singlet phase when particle-hole (P-H) symmetry is maintained. We clarify the circumstances under which this critical point occurs, pointing out that there are two types of P-H symmetry. Only one of them guarantees the occurance of the critical point. Much of the previous numerical work
more » ... was done on models with the other type of P-H symmetry. We analyse this critical point using the boundary conformal field theory technique. The finite-size spectrum is presented in detail and compared with about 50 energy levels obtained using the numerical renormalization group. Various Green's functions, general renormalization group behaviour, and a hidden SO(7) are analysed.
doi:10.1103/physrevb.52.9528 pmid:9980002 fatcat:xdcm4uwhjjcvji5tfmw7jm2biq