Thermal conductivity of λ-(BETS)2GaCl4 under oriented magnetic fields

Thermal conductivity κ of organic superconductor λ-(BETS)2GaCl4 have been studies on samples of varying quality as a function of temperature T, magnetic field strength H and angle of inclination with respect to the conducting plane Θ. The shape of Hc2(T) phase diagram in parallel magnetic field is consistent with Pauli paramagnetic limiting in low quality samples, as supported by a jump-like anomaly in κ(H). In high quality samples the shapes of both the Hc2(T) and κ(H) transform in a way consistent with the formation of Fulde–Ferrel–Larkin–Ovchinnikov state.