Has the FFLO state been observed in the organic superconductor κ-(BEDT-TTF)₂Cu(NCS)₂?

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We compare the theoretical anisotropic upper critical field HC(Θ,T) of a quasi-two-dimensional d-wave superconductor with recent Hc₂ data for the layered organic superconductor κ-(BEDT-TTF)₂Cu(NCS)₂. We find agreement both with regard to the angular and the temperature dependence of HC. This supports the suggestion that the Fulde-Ferrell-Larkin-Ovchinnikov state (FFLO state) exists in this material for exactly plane-parallel orientation of the magnetic field. Indications of precursor states, occurring for small deviations from the plane-parallel field direction, are also pointed out and further measurements for confirming the existence of the FFLO state are proposed.