General form of the local magnetization in the XY chain with impurity

Abstract

Green's function technique in the pseudofermion representation is used to study the oscillation of the local magnetization in the impure spin 1 2 XY chain. The theory described in the previous work is extended to the case when both the exchange integral in the immediate vicinity of the impurity and its g-factor are different from the bulk of the chain. The results are obtained in the closed form and are interpreted in terms of the local density of states. It is shown that Friedel-type oscillations of the spin density, resulting from the different components of the perturbation, have phase shifts depending on the intensity of the external magnetic field.