Scaling theory of magnetism in frustrated Kondo lattices

Abstract

A scaling theory of the Kondo lattices with frustrated exchange interactions is developed, criterium of antiferromagnetic ordering and quantum-disordered state being investigated. The calculations taking into account magnon and incoherent spin dynamics are performed. Depending on the bare model parameters, one or two quantum phase transitions into non-magnetic spin-liquid and Kondo Fermi-liquid ground states can occur with increasing the bare coupling constant. Whereas the renormalization of the magnetic moment in the ordered phase can reach orders of magnitude, spin fluctuation frequency and coupling constant are moderately renormalized in the spin-liquid phase. This justifies application of the scaling approach. Possibility of a non-Fermi-liquid behavior is treated.

Unconventional magnetism and electronic state in the frustrated layered system PdCrO2

“…However, with increasing T we come to an exotic regime with disordered moments. The scaling consideration of magnetic ordering formation in the Kondo lattices with usual spin-wave dynamics [43,44] gives, as a rule, a sharp crossover with a NFL behavior in a narrow region. A scaling theory of the Kondo lattices with frustrated exchange interactions in spirit of the self-consistent spin-wave theory (SSWT), where spin-wave frequency does not vanish in the paramagnetic region [27,35], was presented in Ref.…”

“…A scaling theory of the Kondo lattices with frustrated exchange interactions in spirit of the self-consistent spin-wave theory (SSWT), where spin-wave frequency does not vanish in the paramagnetic region [27,35], was presented in Ref. [44]. This yields, depending on the model parameters, one or two quantum phase transitions into nonmagnetic spinliquid and Kondo Fermi-liquid ground states with increasing the bare coupling constant.…”

“…At the same time, strong short-range order and NFL features are observed in transport properties, so the SSWT picture is insufficient and we have to go beyond spin-wave picture, e.g., including spinon excitations (see discussion in Ref. [44]).…”