Superconducting nano Josephson junctions patterned with a focused helium ion beam
Superconducting nano Josephson junctions patterned with a focused helium ion beam
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DOI：
10.1063/1.5042105
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发表时间：
2018-07-09
影响因子：
4
通讯作者：
Cybart, Shane A.
中科院分区：
文献类型：
--
作者：
Cho, Ethan Y.;Zhou, Yuchao W.;Cybart, Shane A.
我们报道了在25 nm厚的YBa2Cu3O7-Delta薄膜中制备纳米线和约瑟夫森结，线宽仅为50 nm。我们的方法利用来自氦离子显微镜的精细聚焦的气场离子源在纳米尺度上直接对材料进行修饰，将薄膜的受照区域转化为绝缘体。在这种方式下，薄膜保持完好无损，没有任何材料被碾磨或去除。传输数据显示，电学特性，即临界电流和电导，与光刻定义的宽度成线性关系，从而确保实际尺寸和光刻定义的尺寸彼此相称。与典型的离子损伤邻近效应约瑟夫森结不同，我们观察到临界电流和近温度相互依赖电阻的低温饱和，我们将其归因于更窄和更具阻性的势垒。此外，我们还展示了制作具有滞后欠阻尼约瑟夫森结特性的高电阻和高电容的器件的能力。这种图案化技术允许约瑟夫森器件具有广泛的电学特性，这将扩展潜在的应用。由AIP出版公司出版。
We report the fabrication of nanoscale wires and Josephson junctions in 25 nm thick YBa2Cu3O7-delta thin films with wire widths as narrow as 50 nm. Our approach utilizes a finely focused gas field ion source from a helium ion microscope to directly modify the material on the nanometer scale to convert irradiated regions of the film into insulators. In this manner, the film remains intact and no material is milled or removed. Transport data show that the electrical properties, critical current and conductance, scale linearly with the lithographically defined width ensuring that the actual and lithographically defined dimensions are commensurate with each other. Unlike in typical ion damage proximity effect Josephson junctions, we observe a low temperature saturation of the critical current and near temperature interdependent resistance which we attribute to a narrower and more resistive barrier. Furthermore, we also demonstrate the ability to fabricate devices exhibiting high resistance and capacitance with hysteretic underdamped Josephson junction properties. This patterning technique allows for a broad range of electrical properties for Josephson devices that will expand potential applications. Published by AIP Publishing.