Drude weight in quasi-two-dimensional organic conductors

NATALIA DRICHKO , MICHAEL DUMM , DANIEL FALTERMEIER, MARTIN DRESSEL ,JAIME MERINO , ANDRES GRECO

PHYSICA C - SUPERCONDUTIVITY

Elsevier

Año: 2006 vol. 460 p. 125 - 128

0921-4534

We explore the effects of electronic correlations in quasi-two-dimensional BEDT-TTF-based organic conductors with half, quarterand 1/5-filled bands. Close to the Mott transition but still on the metallic side, quasiparticles are observed in the 1/2-filled systems onlyat temperatures well below 100 K, with a considerable growth of the Drude-like contribution. In contrast, the 1/4-filled conductors showa zero-frequency conduction peak already at room temperature which increases slightly upon cooling. Basically no change with temperatureis observed for the Drude contribution of the 1/5-filled compound. Optical studies allow us to investigate the formation of quasiparticlesat low temperature for systems of different filling. The strongest effect is observed in 1/2-filled compounds, it becomes weaker in1/4 filled, while in the 1/5-filled compound no change of the Dude-peak on temperature is seen.