Shimizu Y, Braithwaite D, Aoki D, Salce B, Brison JP. Spin-Triplet p-Wave Superconductivity Revealed under High Pressure in UBe_{13}.
PHYSICAL REVIEW LETTERS 2019;
122:067001. [PMID:
30822059 DOI:
10.1103/physrevlett.122.067001]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Revised: 06/20/2018] [Indexed: 06/09/2023]
Abstract
To unravel the nature of the superconducting symmetry of the enigmatic 5f heavy-fermion UBe_{13}, the pressure dependence of the upper critical field and of the normal state are studied up to 10 GPa. Remarkably, the pressure evolution of the anomalous H_{c2}(T,P) over the entire pressure range up to 5.9 GPa can be successfully explained by the gradual admixture of a field-pressure-induced E_{u} component in an A_{1u} spin-triplet ground state. This result provides strong evidence for parallel-spin pairing in UBe_{13}, which is also supported by the recently observed fully gapped excitation spectrum at ambient pressure. Moreover, we have also found a novel non-Fermi-liquid behavior of the resistivity, ρ(T)∼T^{n} (n≲1), which disappears with the collapse of the negative magnetoresistance behavior and the existence of a superconducting ground state around P=6 GPa, suggesting a close interplay between Kondo scattering and superconductivity.
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