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Anomalous heat capacity of spin triplet superconductor UTe2

ORAL

Abstract

The recently discovered superconducting state in uranium ditelluride is a playground of exotic phenomena, including field-reentrant superconductivity up to sixty tesla and spin-triplet pairing.[1, 2] In addition this system shows a large residual density of states at zero temperature, suggesting that about half of the electrons fail to condense, and an apparent violation of entropy balance across the superconducting transition.[1, 3] This talk will present milikelvin specific heat data on UTe2 as a function of magnetic field applied along multiple crystallographic axes. The specific heat shows an upturn at the lowest temperatures. The form of the upturn in temperature and its evolution in magnetic field suggest that it has its origin in critical ferromagnetic fluctuations, supporting the idea that UTe2 is the paramagnetic end member of the series of uranium-based ferromagnetic superconductors. Furthermore, subtracting this upturn restores entropy balance to the superconducting transition. The talk will conclude with a discussion of the implications of these observations for the triplet pairing scenario.

S. Ran et al, Science 365 684 (2019)
S Ran et al, arxiv:1905:04343 (2019)
T. Metz et al, arXiv:1908.01069 (2019)

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Presenters

  • Ian Hayes

    University of Maryland, College Park, University of California, Berkeley

Authors

  • Ian Hayes

    University of Maryland, College Park, University of California, Berkeley

  • Tristin Metz

    University of Maryland, College Park, Physics Department, University of Maryland, Center for Quantum Materials, University of Maryland

  • Yun Suk Eo

    University of Maryland, College Park, Center for Nanophysics and Advanced Materials, University of Maryland, Maryland Quantum Materials Center, Department of Physics, University of Maryland College Park, Center for Quantum Materials, University of Maryland

  • Sheng Ran

    NIST Center for Neutron Research, National Institute of Standards and Technology, University of Maryland, College Park, National Institute of Standards and Technology, Physics Department, University of Maryland, University of Maryland, University of Maryland, College Park & NIST, Department of Physics, University of Maryland, College Park, NIST Center for Neutron Research

  • Nicholas Butch

    NIST Center for Neutron Research, National Institute of Standards and Technology, National Institute of Standards and Technology, Center of Neutron Research, National Institute of Standards and Technology, Center for Neutron Research, National Institute of Standards and Technology, NIST Center for Neutron Research, NIST center for neutron research, NIST, NIST Center for Neutron Research, National Institute of Standards and Technology,, University of Maryland, College Park & NIST, National Institute of Standards and Technology Center for Neutron Research

  • Johnpierre Paglione

    University of Maryland, College Park, Physics Department, University of Maryland, Maryland Quantum Materials Center, Department of Physics, University of Maryland College Park, Department of Physics, University of Maryland, College Park, University of Maryland, College Park & NIST, Univ of Maryland-Colege Park, Center for Quantum Materials, University of Maryland, Maryland Quantum Materials Center, Department of Physics, University of Maryland-College Park,College Park, Maryland 20742