Strong coupling in the Kondo problem at low temperatures

An average value of spin of a localized electron coupled with conduction el ectrons via exchange interaction is found for the ground state as a functio n of magnetic field. For magnetic fields mu H similar to 0.5T(k) (T-k is th e Kondo temperature) there is an inflection point, wheras for a strong magn etic field mu H much greater than T-k, the deviation of the average spin fr om saturated value is proportional to(T-k/mu H)(2). (C) 2000 Published by E lsevier Science B.V. All rights reserved.