Magnetic Imaging with High Spatial Resolution Using a Single Niobium-Nitride-Based Three-Dimensional Nanobridge...

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Superconducting Quantum Interference Devices (SQUIDs) are crucial for magnetic imaging but face resolution limits.
• Existing nanoSQUIDs are constrained by loop diameter, hindering nanoscale magnetic field mapping.
• Miniaturization of SQUIDs using nanobridge junctions (NBJs) is key to improving spatial resolution.

Purpose of the Study:

• To introduce a single niobium-nitride-based three-dimensional nanobridge junction (NbN-3D-NBJ) as a high-resolution magnetic imaging probe.
• To demonstrate the potential of NbN-3D-NBJs as an alternative to nanoSQUIDs for nanoscale magnetic field mapping.
• To achieve ultrahigh spatial resolution in magnetic imaging beyond the limitations of conventional SQUIDs.

Main Methods:

• Fabrication of a single niobium-nitride-based three-dimensional nanobridge junction (NbN-3D-NBJ).
• Characterization of the critical current dependence on external magnetic fields.
• Utilizing NbN-3D-NBJ probes for magnetic imaging of superconducting vortices and nanowire spacings.

Main Results:

• The NbN-3D-NBJ exhibited a critical current dependence suitable for nanoscale magnetic field mapping with low intrinsic noise (100 nT/√Hz).
• Successful imaging of an Abrikosov vortex in niobium with a 0.53 μm full width at half maxima (FWHM).
• Resolution of 80 nm spacings between superconducting nanowires using an optimized NbN-3D-NBJ probe.

Conclusions:

• The single 3D NbN NBJ probe is a viable and effective tool for magnetic imaging at ultrahigh spatial resolutions.
• NbN-3D-NBJs overcome the resolution limitations imposed by SQUID loop diameters.
• This technology opens new avenues for nanoscale magnetic field analysis and imaging applications.