Suppression of Antiferromagnetism in Electron-Doped Cuprate $T$-${rm La}_{2-x}{rm Ce}_xrm {CuO}_{4pmdelta}$

We performed systematic angle-resolved photoemission spectroscopy measurements $in$-$situ$ on $T$-${rm La}_{2-x}{rm Ce}_xrm {CuO}_{4pmdelta}$ (LCCO) thin films over the extended doping range prepared by the refined ozone/vacuum annealing method. Electron doping level ($n$), estimated from the measured Fermi surface volume, varies from 0.05 to 0.23, which covers the whole superconducting dome. We observed an absence of the insulating behavior around $n sim$ 0.05 and the Fermi surface reconstruction shifted to $n sim$ 0.11 in LCCO compared to that of other electron-doped cuprates at around 0.15, suggesting that antiferromagnetism is strongly suppressed in this material. The possible explanation may lie in the enhanced -$t$ /$t$ in LCCO for the largest $rm{La^{3+}}$ ionic radius among all the Lanthanide elements.