Point contact Andreev reflection spectroscopy on possible chiral superconductor UTe<sub>2</sub>

POSTER

Abstract

Recent findings on a heavy-fermion superconductor, UTe2 such as 1) an exceptionally large and anisotropic upper critical field, 2) a large residual Sommerfeld coefficient, 3) the reentrant superconducting phase in a high magnetic field, and 4) pressure-enhanced superconductivity, have attracted great attention as indication of spin-triplet superconductivity. Scanning tunneling microscopy/spectroscopy measurements and microwave surface impedance measurement on UTe2 have suggested presence of the chiral edge state and normal fluid at the surface as evidence for the chiral spin-triplet pairing symmetry of the superconducting order parameter in UTe2. To further investigate the superconducting order parameter, we are performing point contact Andreev reflection (PCAR) measurements on single-crystal UTe2. PtIr and Nb tips are used to form N(I)/S and S(I)/S point-contact junctions, respectively. Evolution of conductance spectra as a function of temperature, magnetic field, and tip pressure will be discussed.

*This work was supported by AFOSR No. FA9550-14-10332.

Presenters

  • Seunghun Lee

    • University of Maryland, College Park

Authors

  • Seunghun Lee

    • University of Maryland, College Park

  • Xiaohang Zhang

    • University of Maryland, College Park

  • 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

  • Richard Greene

    • University of Maryland, College Park

  • 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

  • Ichiro Takeuchi

    • University of Maryland, College Park