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

✍ Scribed by P. Gegenwart; C. Langhammer; R. Helfrich; N. Oeschler; M. Lang; J.S. Kim; G.R. Stewart; F. Steglich

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 492 KB
• Volume: 408-410
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2004.02.070

✦ Synopsis

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, q, on a high-quality single crystal in magnetic fields up to 15.5 T. At B ¼ 0, unconventional superconductivity forms at T c ¼ 0:9 K out of an incoherent state, characterized by a large and strongly temperature dependent qðT Þ. In the magnetic field interval 4 T 6 B 6 10 T, qðT Þ follows a T 3=2 behavior for T c ðBÞ 6 T 6 1 K, while q 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 ¼ 0) yields a fieldinduced QCP, T L ! 0, at B ¼ 4:5 T.