  Recent emergence of two-dimensional (2D) crystalline superconductors has
provided a promising platform to investigate novel quantum physics and
potential applications. To reveal essential quantum phenomena therein, ultralow
temperature transport investigation on high quality ultrathin superconducting
films is critically required, although it has been quite challenging
experimentally. Here we report a systematic transport study on the ultrathin
crystalline PdTe2 films grown by molecular beam epitaxy (MBE). Interestingly, a
new type of Ising superconductivity in 2D centrosymmetric materials is revealed
by the detection of large in-plane critical field more than 7 times Pauli
limit. Remarkably, in perpendicular magnetic field, we provide solid evidence
of anomalous metallic state characterized by the resistance saturation at low
temperatures with high quality filters. The robust superconductivity with
intriguing quantum phenomena in the macro-size ambient-stable ultrathin PdTe2
films remains almost the same for 20 months, showing great potentials in
electronic and spintronic applications.
