Realization of Kondo chain in CeCo2Ga8

Abstract

We revisited the anisotropy of the heavy-fermion material CeCo2Ga8 by measuring the electrical resistivity and magnetic susceptibility along all the principal a-, b-and c-axes. Resistivity along c-axis (ρc) shows clear Kondo coherence below about 17 K, while both ρa and ρ b remain incoherent down to 2 K. The magnetic anisotropy is well understood within the theoretical frame of crystalline electric field effect in combination with magnetic exchange interactions. We found the anisotropy ratio of these magnetic exchange interactions, |J c ex /J a,b ex |, reaches a large value of 4-5. We, therefore, firmly demonstrate that CeCo2Ga8 is a quasi-one-dimensional heavy-fermion compound both electrically and magnetically, and thus provide a realistic example of Kondo chain.

Large negative magnetoresistance in the antiferromagnetic rare-earth dichalcogenide EuTe2

“…The resistivity has a value of 8.6×10 3 Ω cm at 1.8 K and decreases to 1.3×10 −1 Ω cm at room temperature. The sharp upturn at low temperature is consistent with the hybridization of electrons due to the formation of magnetic order [12][13][14][15] .…”

Anisotropic c−f Hybridization in the Ferromagnetic Quantum Critical Metal CeRh6Ge4Wu1, Zhang2, Du3 et al. 2021Phys. Rev. Lett.333160View full textAdd to dashboardCite

“…Since the magnetic exchange interaction is electronic in nature, the dispersion of quasiparticle bands could also be highly anisotropic, possibly leading to quasi-one-dimensional (1D) electronic states as proposed in YbNi 4 P 2 [9]. Quasi-1D chains of 4f moments are also reported in a few other HF systems, e.g., in CeCo 2 Ga 8 , where non-Fermi-liquid phenomena were also observed [10,11]. However, whether such a chainlike arrangement of 4f moments may indeed lead to quasi-1D or anisotropic 4f bands has not yet been verified by momentum-resolved measurements such as angle-resolved photoemission spectroscopy (ARPES).…”

Quantum Fluctuations in the Non-Fermi Liquid System CeCo$_{2}$Ga$_{8}$ Investigated Using $μ$SR

“…Nevertheless, the T -linear resistivity and a logarithmically divergent-specific heat is expected in the 2D antiferromagnetic QCP from the conventional Hertz-Millis theory 31,32 , but not in a quasi-1D Kondo lattice system. Interestingly in the case of CeCo 2 Ga 8 , anisotropic magnetic attributes well explained utilizing crystal field theory, and the ratio of the exchange interaction is |J c ex /J a,b ex | ∼ 4-5 33 . Our investigation on CeCo 2 Ga 8 includes electrical resistivity ρ(T), dc susceptibility χ(T ), heat capacity C P (T) data used for characterization of CeCo 2 Ga 8 , and muon spin relaxation (µSR) measurement to study the low energy spin dynamics.…”