Flux focusing with a superconducting nanoneedle for scanning SQUID susceptometry
Abstract 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 partic...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Publishing Group
2023-06-01
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| Series: | Microsystems & Nanoengineering |
| Online Access: | https://doi.org/10.1038/s41378-023-00553-9 |
| Summary: | Abstract 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. |
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| ISSN: | 2055-7434 |