A Green's-function method is used to obtain the exact expression for the local susceptibility of the impure spin-1/2 XY chain at zero temperature. The presence of the impurity (or boundary) affects the singularity of the magnetic field dependence of the local susceptibility. The corresponding critical exponent changes from -1/2 to +1/2 at an arbitrary distance from the impurity site. In contrast with the transverse Ising model, the critical exponent is independent of the perturbation strength. This phenomenon is related to the spatial oscillations of the local density of states in the nonideal XY chain. It is also shown that experimental investigation of the field dependence of the finite-temperature macroscopic susceptibility of the one-dimensional XY-like system (such as ${\mathrm{Cs}}_{2}$ ${\mathrm{CoCl}}_{4}$ ) may reveal the formation of the localized states associated with impurities.A Green's-function method is used to obtain the exact expression for the local susceptibility of the impure spin-1/2 XY chain at zero temperature. The presence of the impurity (or boundary) affects the singularity of the magnetic field dependence of the local susceptibility. The corresponding critical exponent changes from -1/2 to +1/2 at an arbitrary distance from the impurity site. In contrast with the transverse Ising model, the critical exponent is independent of the perturbation strength. This phenomenon is related to the spatial oscillations of the local density of states in the nonideal XY chain. It is also shown that experimental investigation of the field dependence of the finite-temperature macroscopic susceptibility of the one-dimensional XY-like system (such as ${\mathrm{Cs}}_{2}$${\mathrm{CoCl}}_{4}$) may reveal the formation of the localized states associated with impurities.

Physical review. B, Condensed matterSep 1, 19854 citations

Oscillations of Local Magnetization in the Non‐Ideal Antiferromagnetic Chain

Gennady Sh. Gildenblat

Abstract A Green's function technique is used to obtain the exact form of the Friedel type oscillations of local magnetization in the spin 1/2, XY antiferromagnetic chain induced by the presence of a boundary or impurity. It is shown that, in addition to the amplitude, the functional form of the oscillations is determined by the strength of the perturbation caused by the impurity and intensity of the external magnetic field. Comparison is made with the earlier perturbation theory treatment in the free‐fermion approximation.Abstract A Green's function technique is used to obtain the exact form of the Friedel type oscillations of local magnetization in the spin 1/2, XY antiferromagnetic chain induced by the presence of a boundary or impurity. It is shown that, in addition to the amplitude, the functional form of the oscillations is determined by the strength of the perturbation caused by the impurity and intensity of the external magnetic field. Comparison is made with the earlier perturbation theory treatment in the free‐fermion approximation.

physica status solidi (b)Dec 1, 19833 citations

Magnetization formula in the bounded XYZ spin chain

Yasuhiro Fujii, Miki Wadati

Chaos Solitons & FractalsJul 1, 20000 citations

{\mathrm{Cs}}_{2}

{\mathrm{CoCl}}_{4}

) may reveal the formation of the localized states associated with impurities.