Pressure dependence of the magnetic penetration depth in kappa-(BEDT-TTF)(2)Cu(NCS)(2) - art. no. 144514

We have measured the magnetic penetration depth lambda in the two-dimension al organic BEDT superconductor kappa-(BEDT-TTF)(2)Cu(NCS)(2) using a superc onducting quantum interference device magnetometer under zero and applied p ressure above T=2 K. We find that 1/lambda (2)proportional ton(s)/m* (super conducting carrier density/effective mass) at T=0.35T(c) decreases with inc reasing pressure, following a linear relationship between T-c and 1/lambda (2) common to high-T-c superconductors (HTSC's). Pressurized BEDT and overd oped HTSC systems, as they approach normal metals, both exhibit a reduction of n(s)/m* from the normal-state value n(n)/m*. A simple BCS condensation (where n(s)=n(n)) is not sufficient to explain this behavior.