The study of 4k(F) CDW in a one-dimensional system, (DMe-DCNQI)(2)Li1-xCux

We systematically study transport and optical properties of charge-transfer salts, (DMe-DCNQI)(2)Li1-xCux (0 less than or equal to x less than or equa l to 1). In the optical studies, we found the two absorption bands, one att ributable to collective excitations associated with 4k(F) CDW (A-band) and the other to single-particle excitations across the Peierls gap (B-band). T he intensity of the former band is almost constant for x less than or equal to 0.29 and steeply increases for x greater than or equal to 0.39. The lat ter band appears around 3000 cm(-1) for 0 less than or equal to x less than or equal to 0.14, and shifts downward for x greater than or equal to 0.17.