Evidence of a Kondo lattice quantum critical point and of non-Fermi liquid behavior in the intercalated layered system V$_{5}$S$_{8}$

TL;DR

This study provides evidence of a Kondo lattice quantum critical point in V$_{5}$S$_{8}$, where antiferromagnetic order and Fermi liquid behavior are suppressed under pressure, indicating non-Fermi liquid behavior near the critical point.

Contribution

It demonstrates the existence of a quantum critical point in V$_{5}$S$_{8}$, revealing the interplay between magnetism and heavy Fermion behavior in a layered system.

Findings

Antiferromagnetic order coexists with Fermi liquid in V$_{5}$S$_{8}$

Critical pressure $P_c = 10$ GPa suppresses magnetic order and Fermi liquid behavior

Evidence of non-Fermi liquid behavior near the quantum critical point

Abstract

By means of a specific heat, susceptibility and high-pressure electrical resistivity study, we show that the local magnetic moments of the intercalated V ions in V$_{5}$S$_{8}$ realize a prototype of Kondo lattice system, where an antiferromagnetic order of the moments coexists with a Fermi liquid in the VS$_{2}$ layers with intermediate heavy Fermion properties. The antiferromagnetic order and the Fermi-liquid behavior are simultaneously suppressed at a critical pressure, $P_c =10$ GPa, signature of a quantum critical point, which supports a Kondo lattice scenario and raises the question whether, in the paramagnetic phase at higher pressures, the heavy quasiparticles survive or form a non-Fermi liquid phase governed by the Kondo interaction.