Quantum Critical Scaling and origin of Non-Fermi-Liquid behavior in Sc${}_{1-x}$U${}_x$Pd${}_3$

Abstract

We use inelastic neutron scattering to study magnetic excitations of Sc${}_{1-x}$U${}_x$Pd${}_3$ for U concentrations ($x=0.25$, 0.35) near the spin glass quantum critical point (QCP). The excitations are spatially incoherent, broad in energy ($E=\hslash \omega$), and follow $\omega /T$ scaling at all wave vectors investigated. Since similar $\omega /T$ scaling has been observed for UCu${}_{5-x}$Pd${}_x$ and CeCu${}_{6-x}$Au${}_x$ near the antiferromagnetic (AF) QCP, we argue that the observed non Fermi liquid (NFL) behavior in these $f$-electron materials arises from the critical phenomena near a T=0 K phase transition, irrespective of the nature of the transition.

Submitted to PRL