D-wave Superconductivity in κ-(BEDT-TTF))2Cu(NCS)2

The peak in the out-of-plane magnetoresistance in organic superconductors, κ-(BEDT-TTF))2Cu(NCS)2 is analysed in terms of the standard superconducting fluctuation theory. A similar analysis has been done by Varlamov and his coworkers on the c-axis magnetoresistance in high Tc cuprate superconductors. However, unlike high Tc cuprates, the organic superconductors are in the clean limit. Then the peak in the out-of-plane magnetoresistance indicates that the superconductivity in the organic superconductor is not of s-wave, but of d-wave. Further possible p-wave superconductivity in Bechgaard salts is described.