From measurements of the magnetic penetration depth, lambda(T), from 1.6 K to T-c in films of electron-doped cuprates La2-xCexCuO4-y and Pr2-xCexCuO4-y we obtain the normalized density of states, N-s(E) at T=0 by using a simple model. In this framework, the flat behavior of lambda(-2)(T) at low T implies N-s(E) is small, possibly gapped, at low energies. The upward curvature in lambda(-2)(T) near T-c seen in overdoped films implies that superfluid comes from an anomalously small energy band within about 3k(B)T(c) of the Fermi surface.
|Journal||Journal of Low Temperature Physics|
|Publication status||Published - 2001|
|Event||International Conference on Physics and Chemistry of Molecular and Oxide Superconductors (MOS2002) - Hsinchu, Taiwan, Province of China|
Duration: 13 Aug 2002 → 18 Aug 2002
|Conference||International Conference on Physics and Chemistry of Molecular and Oxide Superconductors (MOS2002)|
|Country||Taiwan, Province of China|
|Period||13/08/2002 → 18/08/2002|