Time-resolved optical study on BETS superconductors and related salts

In order to compare the carrier dynamics in λ-(BETS)2MCl4 (M=Ga, Fe) and κ-(ET)2X (X=Cu(NCS)2, Cu[N(CN)2]Br, Cu[N(CN)2]Cl), their polarized reflectance spectra were measured by a pump–probe method. Polarization-dependences were compared among the different materials at varying temperatures. The result indicated that each salt had anisotropy in the conduction planes corresponding to its crystallographic axes at all the temperatures of measurements.