The Quantum Critical Point in CeRhIn₅: A Resistivity Study

Abstract

The pressure-temperature phase diagram of CeRhIn5 has been studied under high magnetic field by resistivity measurements. Clear signatures of a quantum critical point has been found at a critical pressure of pc ≈ 2.5 GPa. The field induced magnetic state in the superconducting state is stable up to the highest field. At pc the antiferromagnetic ground-state under high magnetic field collapses very rapidly. Clear signatures of pc are the strong enhancement of the resistivity in the normal state and of the inelastic scattering term. No clear T 2 temperature dependence could be found for pressures above Tc. From the analysis of the upper critical field within a strong coupling model we present the pressure dependence of the coupling parameter λ and the gyromagnetic ratio g. No signatures of a spatially modulated order parameter could be evidenced. A detailed comparison with the magnetic field-temperature phase diagram of CeCoIn5 is given. The comparison between CeRhIn5 and CeCoIn5 points out the importance to take into account the field dependence of the effective mass in the calculation of the superconducting upper critical field Hc2. It suggests also that when the magnetic critical field HM(0) becomes lower than Hc2(0), the persistence of a superconducting pseudo-gap may stick the antiferromagnetism to Hc2(0).

Drastic Change of Electronic Properties in Ce2MgSi2 and CeNiIn4 under High Pressure

“…In several heavy fermion materials, the residual resistivity as a function of pressure indicates a maximum at the quantum critical point, as in CeRhIn 5 [4]. It is, however, noted that the low-temperature resistivity, ρ(T ), even in the quantum critical region in CeRhIn 5 has a maximum at a characteristic temperature, and decrease at lower temperatures.…”

Heavy fermion superconductor CeCu2Si2under high pressure: Multiprobing the valence crossover

“…The latter scenario is also assumed in CeRhIn 5 , mainly based on the subsistence of SC in a wide region around p c , the maximum in ρ 0 , and a T -linear resistivity (n ∼ 1). [32][33][34] Using our method could be an important ingredient for probing the existence of a CEP and the relevancy of VF, notably for SC, in these compounds. Nonetheless, another dissimilarity to CeCu 2 Si 2 may occur: The resistance drop associated with the delocalization may be less pronounced, which means experimentally less accessible, due to a lower lying CEP (more negative T cr ).…”

Quantum criticality in layered \chem{{CeRhIn}_{5-{x}}Sn_{x}} compared with cubic \chem{{CeIn}_{3-{x}}Sn_{x}}

“…1 Hydrostatic pressure experiments have been performed on cubic CeIn 3 (Néel temperature T N at ambient pressure about 10 K) as well as layered CeRhIn 5 (T N = 3.8 K). In both cases, the AF ordering vanishes discontinuously as a function of applied pressure [18][19][20], and the nature of the f -electrons, as determined from de Haas-van Alphen (dHvA) experiments at low temperatures and high mag- …”

“…Although the low-T electrical resistivity of CeIn 3 has shown an anomalous exponent of 1.6 [10], nuclear quadrupole resonance suggests a Landau Fermi liquid ground state [18], and the cyclotron mass derived from dHvA experiments is constant near the discontinuous QPT [21]. For CeRhIn 5 the cyclotron mass m ⋆ (p) [21] and the coefficient A(p) of T 2 behavior in the electrical resistivity at 15 T [20] show diverging behavior, suggesting a field-induced QCP close to p c ≈ 2.5 GPa. Previously it has been demonstrated, that Sn-doping in CeIn 3−x Sn x [22] as well as CeRhIn 5−x Sn x [23,24] leads to a continuous suppression of AF order without formation of SC around the QCP.…”