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arXiv · 1511.03266

Metallic ground state in an ion-gated two-dimensional superconductor

Yu Saito·Yuichi Kasahara·Jianting Ye·Yoshihiro Iwasa·Tsutomu Nojima
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Abstract

Recently emerging two-dimensional (2D) superconductors in atomically thin layers and at heterogeneous interfaces are attracting growing interest in condensed matter physics. Here, we report that ion-gated ZrNCl surface, exhibiting a dome-shaped phase diagram with a maximum critical temperature of 14.8 kelvin, behaves as a superconductor persisting to the 2D limit. The superconducting thickness estimated from the upper critical fields is ~ 1.8 nanometers, which is thinner than one-unit-cell. The majority of the vortex phase diagram down to 2 kelvin is occupied by a metallic state with a finite resistance, owing to the quantum creep of vortices caused by extremely weak pinning and diminishing disorder. Our findings highlight the potential of electric-field-induced superconductivity, establishing a new platform for accessing quantum phases in clean 2D superconductors.

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Yu Saito, Yuichi Kasahara, Jianting Ye, Yoshihiro Iwasa, Tsutomu Nojima. 2015-11-10. Metallic ground state in an ion-gated two-dimensional superconductor. https://doi.org/10.1126/science.1259440

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