Type-II Ising superconductivity and anomalous metallic state in macro-size ambient-stable ultrathin crystalline films

TL;DR

This study uncovers a new type of Ising superconductivity and an anomalous metallic state in high-quality ultrathin PdTe2 films, demonstrating stable quantum phenomena with potential applications in electronics and spintronics.

Contribution

It reports the discovery of a novel Ising superconductivity and an anomalous metallic state in ultrathin PdTe2 films, advancing understanding of 2D quantum phenomena in centrosymmetric materials.

Findings

Large in-plane critical field exceeds 7 times Pauli limit.

Resistance saturation at low temperatures indicates anomalous metallic state.

Superconductivity remains stable over 20 months in ambient conditions.

Abstract

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.