Comparative study of the pressure effects on the magnetic penetration depth in electron- and hole-doped cuprate superconductors.

The effect of pressure on the magnetic penetration depth λ was tested for the hole-doped superconductor YBa(2)Cu(3)O(7-δ) and in the electron-doped one Sr(0.9)La(0.1)CuO(2) by means of magnetization measurements. Whereas a large change of λ was found in YBa(2)Cu(3)O(7-δ), confirming the non-adiabatic character of the electron-phonon coupling in hole-doped superconductors, the same quantity is not affected by pressure in electron-doped Sr(0.9)La(0.1)CuO(2), suggesting a close similarity of the latter to conventional adiabatic Bardeen-Cooper-Schrieffer superconductors. The present results imply a remarkable difference between the electronic properties of hole-doped cuprates and electron-doped Sr(0.9)La(0.1)CuO(2), giving a strong contribution to the long debated asymmetric consequences of hole and electron doping in cuprate superconductors.