Non-Fermi liquid regime in metallic pyrochlore iridates: Quantum Griffiths singularities

Abstract

We investigate the interplay of Kondo and RKKY coupling in presence of disorder by chemically substituting local moment Cr^{3+} at the Ir sublattice in the metallic Pr_{2}Ir_{2}O_{7}. We find evidence of non-Fermi liquid (NFL) behaviour in the transport and thermodynamic measurements at low temperature. Specifically, the magnetic susceptibility exhibits power law divergence at T=0. The nonanalytic temperature and magnetic-field dependence of magnetic susceptibility and the associated scaling suggest existence of a two-fluid system consisting of Kondo-screened paramagnetic metal coexisting with magnetically ordered rare regions dominated by inter-impurity interaction, similar to quantum critical Griffiths phase.

7 pages and 4 figs

References in corpus (7)

• Quantum Valence Criticality as Origin of Unconventional Critical Phenomena
• Comparative studies of low temperature X-ray diffraction experiments on R2Ir2O7 (R = Nd, Eu, and Pr)
• Ordering of the pyrochlore Ising model with the long-range RKKY interaction
• Chiral RKKY interaction in Pr2Ir2O7
• Anomalous lattice contraction and emergent electronic phases in Bi-doped Eu${}_2$Ir${}_2$O${}_7$
• Colossal enhancement of electrical conductivity in Y2Ir2O7 nanoparticles
• Coexistence of high electrical conductivity and weak ferromagnetism in Cr doped Y${}_2$Ir${}_2$O${}_7$ pyrochlore iridate

Cited by in corpus (1)

• Identification of Griffiths-like phase and its evolution in Cr substituted pyrochlore iridates $Y_{2}I{r}_2{O}_7$