Metallic ground state in an ion-gated two-dimensional superconductor
Metallic ground state in an ion-gated two-dimensional superconductor
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DOI：
10.1126/science.1259440
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发表时间：
2015-10-23
期刊：
影响因子：
56.9
通讯作者：
Nojima, Tsutomu
中科院分区：
文献类型：
--
作者：
Saito, Yu;Kasahara, Yuichi;Nojima, Tsutomu
最近出现的原子薄层和异质界面的二维（2D）超导体吸引了凝聚态物理越来越多的兴趣。在这里，我们报告说，离子门氮化锆氯化物表面，表现出圆顶形的相图与14.8开尔文的最大临界温度，作为一个超导体坚持到2D极限的行为。由上临界场估计的超导厚度为1.8纳米，比一个单胞还要薄。由于极弱的钉扎和无序引起的涡旋的量子蠕变，在2开尔文以下的涡旋相图的大部分被具有有限电阻的金属态占据。我们的研究结果突出了电场诱导超导的潜力，建立了一个新的平台，在清洁的二维超导体中访问量子相位。
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 an ion-gated zirconium nitride chloride 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 congruent to 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 disorder. Our findings highlight the potential of electric-field-induced superconductivity, establishing a new platform for accessing quantum phases in clean 2D superconductors.