Microscopic Study of the Fulde-Ferrell-Larkin-Ovchinnikov State in an All-Organic Superconductor

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • G. Koutroulakis - , University of California at Los Angeles (Author)
  • H. Kühne - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • J. A. Schlueter - , Argonne National Laboratory, National Science Foundation (Author)
  • J. Wosnitza - , Chair of Physics of High Magnetic Fields, Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • S. E. Brown - , University of California at Los Angeles (Author)

Abstract

Quasi-two-dimensional superconductors with a sufficiently weak interlayer coupling allow magnetic flux to penetrate in the form of Josephson vortices for in-plane applied magnetic fields. A consequence is the dominance of the Zeeman interaction over orbital effects. In the clean limit, the normal state is favored over superconductivity for fields greater than the paramagnetic limiting field, unless an intermediate, inhomogeneous state is stabilized. Presented here are nuclear magnetic resonance (NMR) studies of the inhomogeneous Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state for β′′-(ET)2SF5CH2CF2SO3. The uniform superconductivity-FFLO transition is identified at an applied field value of 9.3(0.1) T at low temperature (T=130 mK), and evidence for a possible second transition between inhomogeneous states at ∼11 T is presented. The spin polarization distribution inferred from the NMR absorption spectrum compares favorably to a single-Q modulation of the superconducting order parameter.

Details

Original languageEnglish
Article number067003
JournalPhysical review letters
Volume116
Issue number6
Publication statusPublished - 12 Feb 2016
Peer-reviewedYes

Keywords

ASJC Scopus subject areas