| author: |
Igor N. Karnaukhov Institute of Metal Physics, Vernadsky Street 36, 03142 Kiev, Ukraine |
We study the effects of a particular type of magnetic impurity in the Lai-Sutherland chain by means of the exact solution through the Bethe ansatz method. We consider the situation where the hard-core fermions are described in the framework of the Lai-Sutherland model and the defect is allowed to move along the chain. In contrast to a traditional approach where an impurity is localized we study the model of strongly correlated electrons with a random walk impurity. The specific of the model proposed follows from the electron -impurity interaction: an impurity is moved due to scattering of electrons on impurity. A random walking of an impurity is realized if the dynamics of fermions, interacting with the impurity, is not frozen.
We have calculated the ground state impurity properties - the valency of impurity, local magnetic moment. We show that depending on the coupling of the impurity to the host, the impurity can either to totally screened or unscreened. In contrast with the Kondo problem there is not crossover from a linear behavior for small fields to a constant value at large fields. We show that the behavior of the impurity is nonuniversal and depends on the coupling between the electrons in the host and that of the electrons to the impurity.