Multiple vortex phases in the heavy fermion superconductor CeCoIn$_{5}$

ORAL

Abstract

We report the entire HT-phase diagram of the vortex lattice (VL) in CeCoIn$_{5}$ for fields applied along the crystallographic $c$-axis. At the upper critical field $H_{c2}$ of about 5~T and 50~mK, we observe a distorted hexagonal flux lattice, which first gives way to a rhombic lattice at 4.3~T and then to a square lattice at 3.3~T, before entering the previously reported flux lattices at lower fields. The distorted hexagonal phase extends to lower fields and higher temperatures than the $H$-$T$-phase space that was previously assigned to a inhomogeneous FFLO state by magnetization and NMR measurements. Surprisingly, we also observed an increase of the flux lattice form factor as a function of increasing field in the rhombic phase, in constrast to the flux lattice in most superconductors. We will discuss the relevance of these results for the presence of the FFLO and magnetic phases.

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Authors

  • A. D. Bianchi

  • Zachary Fisk

    • Dept. Phys. \& Astro., UC Irvine, Irvine, CA, USA
    • University of California, Irvine

  • Michel Kenzelmann

    • ETH/PSI
    • ETH Zurich
    • ETH, Zurich, Switzerland

  • J. Mesot

  • J. Kohlbrecher

  • M. Zolliker

    • LNS, PSI \& ETHZ, Switzerland

  • L. DeBeer-Schmitt

  • M. R. Eskildsen

    • Dept. of Physics, University of Notre Dame, Notre Dame, IN, USA

  • J. S. White

  • E. M. Forgan

    • School of Phys. and Astro., U. of Birmingham, Birmingham, UK

  • R. Movshovich

  • E. D. Bauer

    • Los Alamos National Laboratory

  • John Sarrao

    • Los Alamos National Lab.
    • MPA-10, LANL, Los Alamos, NM, USA
    • Los Alamos National Laboratory
    • Los Alamos Nat. Lab.

  • Cedomir Petrovic

    • Brookhaven National Laboratory
    • Condensed Matter Physics, Brookhaven National Laboratory, Upton NY 11973
    • Cond. Matt. Phys., BNL, Upton, NY 11973, USA
    • Condensed Matter Physics Department, Brookhaven National Laboratory, Upton, New York 11973, USA
    • Condensed Matter Physics Department Brookhaven National Laboratory