Tunneling spectroscopy of e-doped cuprates

Point-contact tunneling spectra were measured on electron-doped high-T$_{c}$ cuprates (NCCO and PLCCO). By phenomenological analysis, we found that the superconducting gap ($\Delta _{sc})$ definitely decreases towards zero in an almost universal law with continuously increasing temperature or magnetic field. At the fields above H$_{c2}$, a clear ``pseudogap'' was opened indicated by the obvious spectral losing below a characteristic energy scale ($\Delta _{pg})$ which is much larger than $\Delta _{sc}$. All the phenomena observed here seem to be crucial to distinguish the mechanism of HTSC and need to be extensively studied on more doping levels.