Spin liquid in 3D Kondo lattice. High temperature regime

TL;DR

This paper proposes a mechanism where antiferromagnetic correlations induce a spin liquid state in a 3D Kondo lattice at high temperatures, highlighting the transition from localized spins to a strongly correlated, quasi-itinerant spin liquid.

Contribution

It introduces a new understanding of how AFM correlations lead to a spin liquid state in 3D Kondo lattices, emphasizing the role of critical spin fluctuations.

Findings

Critical spin fluctuations transform the transition into a crossover.

The spin liquid state is close to magnetic instability.

Short-range or long-range AFM order is expected at low T.

Abstract

The mechanism explaining the key role of AFM correlations in formation of the heavy fermion state is offered. It is shown that in the case of $(T^*-T_N)/T_N << 1$ the critical spin fluctuations transform the mean-field second-order transition to RVB state into the crossover from high-temperature paramagnetic behavior of localized spins to strongly correlated spin liquid with quasi itinerant character of susceptibility. Thus the spin liquid state {\it by its origin} is close to magnetic instability, so either short-range or long-range AFM order should arise at low T.