Boundary effects on static spin correlation functions in the isotropicX—Y chain at zero temperature

Abstract

In this work the static spin correlation of an isotropicX—Y-chain with free ends at zero temperature is dealt with. Following the method of Lieb, Schultz, Mattis the problem is reduced to the evaluation of a determinant of the Cauchy type. With regard to the transverse correlation function we find a change from aR −3/4 to aR −1/2 behavior if the correlated spins move away from the boundary at fixed mutual distanceR.