3D nano-bridge-based SQUID susceptometers for scanning magnetic imaging of quantum materials

Abstract

We designed and fabricated a new type of superconducting quantum interference device (SQUID) susceptometers for magnetic imaging of quantum materials. The 2-junction SQUID sensors employ 3D Nb nano-bridges fabricated using electron beam lithography. The two counter-wound balanced pickup loops of the SQUID enable gradiometric measurement and they are surrounded by a one-turn field coil for susceptibility measurements. The smallest pickup loop of the SQUIDs were 1 $\mu m$ in diameter and the flux noise was around 1 $\mu {\Phi }_0/\sqrt{Hz}$ at 100 Hz. We demonstrate scanning magnetometry, susceptometry and current magnetometry on some test samples using these nano-SQUIDs.

References in corpus (13)

• Scanning nano-SQUID with single electron spin sensitivity
• Imaging currents in HgTe quantum wells in the quantum spin Hall regime
• Nano Superconducting Quantum Interference device: a powerful tool for nanoscale investigations
• Self-aligned nanoscale SQUID on a tip
• Images of edge current in InAs/GaSb quantum wells
• Scanning SQUID susceptometers with sub-micron spatial resolution
• Imaging resonant dissipation from individual atomic defects in graphene
• Superconducting properties of very high quality NbN thin films grown by high temperature chemical vapor deposition
• A Terraced Scanning Superconducting Quantum Interference Device Susceptometer with Sub-Micron Pickup Loops
• Optimizing Anharmonicity in Nanoscale Weak Link Josephson Junction Oscillators
• A high performance Nb nano-SQUID with a three-dimensional structure
• An integrated capacitance bridge for high-resolution, wide temperature range quantum capacitance measurements
• The response of small SQUID pickup loops to magnetic fields

Cited by in corpus (10)

• Observation of robust edge superconductivity in Fe(Se,Te) under strong magnetic perturbation
• Direct observation of quantum anomalous vortex in Fe(Se,Te)
• Oscillating paramagnetic Meissner effect and Berezinskii-Kosterlitz-Thouless transition in $B{i}_{2}S{r}_{2}CaC{u}_2{O}_{8+\delta }$ monolayer
• Direct observation of chiral edge current at zero magnetic field in odd-layer MnBi${}_2$Te${}_4$
• Helical Luttinger liquid on the edge of a 2-dimensional topological antiferromagnet
• Frustrated ferromagnetic transition in AB-stacked honeycomb bilayer
• Geometric Scaling of the Current-Phase Relation of Niobium Nano-Bridge Junctions
• Observation of vortex stripes in UTe${}_2$
• Improving spatial resolution of scanning SQUID microscopy with an on-chip design
• Magnetic Imaging with High Spatial Resolution Using a Single Niobium-Nitride-Based Three-Dimensional Nanobridge Junction