An analysis of the dynamical magnetic susceptibility in non-Fermi liquids

In recent years there has been growing interest in the existence of strongl y correlated, non-Fermi-liquid states with (incipient) phase transitions at zero temperature. A unifying model of the dynamical magnetic susceptibilit y, chi (q, omega), in the non-Fern-ii-liquid state at a finite temperature above such a quantum critical point is presented which addresses the analys is of both inelastic neutron scattering and thermodynamic experiments on a wide range of materials. The functional forms and symmetries of chi (q, ome ga) derived fromthese analyses may serve to guide further experimental and theoretical efforts in elucidating the non-Fem-ii-liquid state, in addition to furnishing the basis for semi-microscopical calculations of thermodynam ic and transport properties.