Proximity Effect in Electron-Doped Cuprate Josephson junctions

We study the proximity effect in Josephson junctions made from electron-doped high-T$_c$ cuprates Pr$_{2-x}$Ce$_x$CuO$_4$ (PCCO) as the electrodes and the barrier. For the electrodes, we use superconducting optimally doped PCCO (x = 0.15). PCCO x = 0.05, an antiferromagnetic metal, is used for the barrier. Our results demonstrate: 1) a conventional proximity effect; 2) but a coupling even if the barrier is antiferromagnetic. We determine the normal coherence length, $\xi _n$, which quantifies the extent of the pair wavefunction into the metal. Comparing this value with the theoretical expectations, we confirm that the coupling appears to be conventional through PCCO x = 0.05. Further results investigating the coupling through an insulating antiferromagnetic barrier and through a metal with no antiferromagnetic order will also be presented.