Self-consistent spin susceptibility in 2D frustrated antiferromagnet

A theory of the dynamical spin susceptibility χ(q,ω) for 2D quantum frustrated S=1/2 Heisenberg model is developed to treat the experiment on magnetic response scaling. The approach is based on a spherically-symmetrical self-consistent scheme for the Green's function, which allows to determine the explicit form of the spin excitation spectrum. It is shown, that scaling can be explained when the temperature dependence of the excitations damping is taken into account. Damping is deduced form the formally exact expression for the Green's function. Its temperature dependence is determined by the best fit for the scaling.