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Non-Fermi liquid normal state of the Heavy Fermion superconductor UBe13

P. Gegenwart·C. Langhammer·R. Helfrich·N. Oeschler·M. Lang·J. S. Kim·G. R. Stewart·F. Steglich
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Abstract

Non-Fermi liquid (NFL) behavior in the normal state of the heavy-fermion superconductor UBe13 is studied by means of low-temperature measurements of the specific heat, C, and electrical resistivity, ρ, on a high-quality single crystal in magnetic fields up to 15.5 T. At B=0, unconventional superconductivity forms at Tc=0.9 K out of an incoherent state, characterized by a large and strongly temperature dependent ρ(T). In the magnetic field interval 4 T \leq B \leq 10 T, ρ(T) follows a T^3/2 behavior for Tc(B)\leq T \leq 1 K, while ρis proportional to T at higher temperatures. Corresponding Non-Fermi liquid behavior is observed in C/T as well and hints at a nearby antiferromagnetic (AF) quantum critical point (QCP) covered by the superconducting state. We speculate that the suppression of short-range AF correlations observed by thermal expansion and specific heat measurements below T_L \simeq 0.7 K (B=0) yields a field-induced QCP, T_L \to 0, at B=4.5 T.

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P. Gegenwart, C. Langhammer, R. Helfrich, N. Oeschler, M. Lang, J. S. Kim, G. R. Stewart, F. Steglich. 2003-07-17. Non-Fermi liquid normal state of the Heavy Fermion superconductor UBe13. https://doi.org/10.1016/j.physc.2004.02.070

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