Thermoelectric power of anisotropic electron system in quasi-one-dimensional organic conductors

We investigate thermoelectric power of Bechgaard salts. Metallic state can clearly be divided into two regions where the linearly temperature dependent thermoelectric power along the most conducting direction has distinct slopes. Thermoelectric power along the second and the least conducting direction has a broad maximum between 50 and 150K depending on the direction or compounds, which is contradictory to the old investigation in early eighties. Our results suggest that the high temperature metallic state is highly one dimensional with b- and c- axis transport being only diffusive. We also suggest that thermoelectric power measurement could be used to estimate the dimerization gap which resides on the most of the quasi-one-dimensional electron system.