Quantum criticality in CeRh0.58Ir0.42In5: Kondo-breakdown and spin-density critical points
نویسندگان
چکیده
Charge and entropy transport properties of the heavy-fermion compound CeRh0.58Ir0.42In5 were measured as a function of pressure. At atmospheric pressure, local moments in the compound order antiferromagnetically below TN=3.5 K, and coexisting superconductivity develops below T on c =1.04 K. Applying pressure suppresses magnetic order, but a potential quantum-critical point is hidden by a dome of superconductivity. Suppressing superconductivity with an applied magnetic field, however, reveals two quantum-critical points. The in-field thermopower divided by temperature changes discontinuously at pc1 and reaches a symmetric peak about pc2. These charge and entropy transport measurements reveal two qualitatively different quantum-critical points in CeRh0.58Ir0.42In5: Kondo-breakdown quantum criticality at pc1 that involves an abrupt reconstruction of Fermi surface is followed by a spin-density critical point at pc2 across which the Fermi surface evolves smoothly. Such a sequence of critical points is anticipated by theoretical predictions for a “global” phase diagram of heavy-fermion materials.
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