Mott Transition and Transport Crossovers in the Organic Compoundκ−(BEDT−TAuthor(s) - Patrice Limelette, P. Wzietek, Serge Florens, Antoine Georges, T. A. Costi, C. Pasquier, D. Jérôme, Cécile Meźière, Patrick Batail

We have performed in-plane transport measurements on the two-dimensionalorganic salt $\kappa$-(BEDT-TTF)$_{2}$Cu[N(CN)$_{2}$]Cl. A variable (gas)pressure technique allows for a detailed study of the changes in conductivitythrough the insulator-to-metal transition. We identify four different transportregimes as a function of pressure and temperature (corresponding to insulating,semi-conducting, ''bad metal'', and strongly correlated Fermi liquidbehaviours). Marked hysteresis is found in the transition region, whichdisplays complex physics that we attribute to strong spatial inhomogeneities.Away from the critical region, good agreement is found with a dynamicalmean-field calculation of transport properties using the numericalrenormalization group technique.Comment: 4 pages, 6 figure