Regensburg 2019 – wissenschaftliches Programm
TT 57.8: Vortrag
Donnerstag, 4. April 2019, 17:00–17:15, H7
Spatial modulation of the superconducting order parameter: A microscopic study of the FFLO state in an all-organic superconductor — •Sebastian Molatta1,2, H. H. Wang3, G. Koutroulakis3, J. A. Schlueter4, J. Wosnitza1,2, S. E. Brown3, and H. Kühne1 — 1Hochfeld-Magnetlabor Dresden (HLD-EMFL), Dresden, Germany — 2Institut für Festkörper und Materialphysik, TU Dresden, Germany — 3Department of Physics and Astronomy, UCLA, Los Angeles, USA — 4Division of Materials Research, National Science Foundation, Arlington, USA
The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state was theoretically predicted in 1964. A hallmark of this state is the spatial modulation of the superconducting order parameter, caused by a strong spinpopulation imbalance of a Fermi liquid. So far, experimental signatures of this superconducting state were found in only very few materials. Recently, microscopic evidence for spatially modulated superconductivity was found by nuclear magnetic resonance (NMR) spectroscopy. We report on our latest results of a comprehensive NMR study of the all-organic superconductor β″-(ET)2SF5CH2CF2SO3, focused on the spectroscopic investigation of the spatial inhomogeneous distribution of the local spin susceptibility in the FFLO phase, with related signatures in the nuclear spin-lattice relaxation rate. The inhomogeneous broadening of the 13C-NMR spectra, as well as the frequencydependent distribution of spin-lattice relaxation times is consistent with a one-dimensional sinusoidally modulated superconducting order parameter in the FFLO state.