Superconducting quantum devices, due to their ultra-low power consumption, high sensitivity and high speed, have attracted great attention in recent years and put forward higher requirements for fabrication technology. Here, we report on the first superconducting ultrathin FeSe nanowires on SrTiO₃ substrates successfully fabricated by electron beam lithography and Ar plasma ion beam etching. As the superconductivity of the molecular beam epitaxial ultrathin FeSe film is highly susceptible by moisture and oxygen, FeTe layers were deposited for protection. We synthesized a superconducting ∼300 nm wide, ∼1.1 nm thick ultrathin FeSe nanowire with TCZero≈5 K (the critical temperature of zero resistance), as revealed by electrical transport measurements. The proper synthesis conditions of the high-quality ultrathin superconducting FeSe nanowires on SrTiO₃ substrates are evaluated by analyzing the morphology and physical properties of the ∼300 nm width ultrathin FeSe nanowire. Our work may pave the way for future applications of air-sensitive iron-based superconducting films.

中文翻译：

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SrTiO3 衬底上超薄超导 FeSe 纳米线的表征

超导量子器件由于具有超低功耗、高灵敏度和高速等特点，近年来备受关注，对制备技术提出了更高的要求。在这里，我们报告了通过电子束光刻和 Ar 等离子体离子束蚀刻成功在 SrTiO ₃基板上制造的第一条超导超薄 FeSe 纳米线。由于分子束外延超薄 FeSe 薄膜的超导性极易受水分和氧气的影响，因此沉积 FeTe 层进行保护。我们合成了一种超导~300 nm 宽、~1.1 nm 厚的超薄 FeSe 纳米线 吨C零≈5个 钾 （零电阻的临界温度），如电传输测量所揭示的那样。通过分析 ~300 nm 宽超细 FeSe 纳米线的形貌和物理性质，评估了在 SrTiO ₃衬底上高质量超细超导 FeSe 纳米线的适当合成条件。我们的工作可能为未来空气敏感铁基超导薄膜的应用铺平道路。