Xiang B K, Wang S Y, Wang Y F, Zhu J J, Xu H T, Wang Y H
State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433 Shanghai, China.
Shanghai Research Center for Quantum Sciences, 201315 Shanghai, China.
Microsyst Nanoeng. 2023 Jun 12;9:78. doi: 10.1038/s41378-023-00553-9. eCollection 2023.
A nanofabricated superconducting quantum interference device (nano-SQUID) is a direct and sensitive flux probe used for magnetic imaging of quantum materials and mesoscopic devices. Due to the functionalities of superconductive integrated circuits, nano-SQUIDs fabricated on chips are particularly versatile, but their spatial resolution has been limited by their planar geometries. Here, we use femtosecond laser 3-dimensional (3D) lithography to print a needle onto a nano-SQUID susceptometer to overcome the limits of the planar structure. The nanoneedle coated with a superconducting shell focused the flux from both the field coil and the sample. We performed scanning imaging with such a needle-on-SQUID (NoS) device on superconducting test patterns with topographic feedback. The NoS showed improved spatial resolution in both magnetometry and susceptometry relative to the planarized counterpart. This work serves as a proof-of-principle for integration and inductive coupling between superconducting 3D nanostructures and on-chip Josephson nanodevices.
一种纳米制造的超导量子干涉器件（纳米超导量子干涉器件）是一种用于量子材料和介观器件磁成像的直接且灵敏的磁通探测器。由于超导集成电路的功能，在芯片上制造的纳米超导量子干涉器件特别通用，但其空间分辨率一直受到其平面几何结构的限制。在这里，我们使用飞秒激光三维（3D）光刻技术在纳米超导量子干涉器件磁强计上打印一根针，以克服平面结构的限制。涂有超导壳的纳米针聚焦了来自励磁线圈和样品的磁通。我们使用这种带有针的超导量子干涉器件（NoS）在具有地形反馈的超导测试图案上进行了扫描成像。与平面化的对应物相比，NoS在磁力测量和磁化率测量中均显示出更高的空间分辨率。这项工作为超导3D纳米结构与片上约瑟夫森纳米器件之间的集成和电感耦合提供了原理验证。
