de Haas-van Alphen study of two-dimensional superconductivity in κ-(BEDT-TTF)2Cu(NCS)2

The de Haas-van Alphen (dHvA) effect in the organic superconductor kappa-(BEDT-TTF)(2)Cu(NCS)(2) has been measured in fields up to 13.6 T, and temperatures in the range 30 mK to 0.5 K. The rHvA signal suffers an additional attenuation associated with the onset of superconductivity. The weak temperature dependence of this additional attenuation factor suggests the involvement of quantum superconducting fluctuations.