Non-Fermi liquid normal state of the heavy-fermion superconductor UBe13

Abstract Non-Fermi liquid (NFL) behavior in the normal state of the heavy-fermion superconductor UBe 13 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 T c =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 ⩽B⩽10 T , ρ ( T ) follows a T 3/2 behavior for T c ( B )⩽ T ⩽1 K, while ρ is 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 ≈0.7 K ( B =0) yields a field-induced QCP, T L →0, at B =4.5 T.