Extended versus local fluctuations in quantum critical Ce(Ru1-xFex)2Ge2 (x = xc = 0.76)

Abstract

We present inelastic neutron scattering experiments, performed near the antiferromagnetic quantum critical point in Ce(Ru0.24Fe0.76)2Ge2. Both local and long-range fluctuations of the local moments are observed, but due to the Kondo effect only the latter are critical. We propose a phenomenological expression which fits the energy E, temperature T, and wave vector q dependences of the dynamic susceptibility, describing the non-Fermi liquid E=T scaling found at every q