This paper proposes a comprehensive methodological framework for spatially-resolved imaging of broken time-reversal symmetry (BTRS) domains using advanced scanning SQUID microscopy with sub-100 nm resolution. The approach targets chiral p-wave superconductors such as Sr2RuO4, providing theoretical analysis of magnetic signatures from domain walls, edges, and defects. The work establishes experimental protocols including field-cooling procedures and data analysis algorithms for domain reconstruction, addressing challenges like thermal drift and flux trapping to enable definitive characterization of BTRS domain structures.
Key findings
Developed comprehensive scanning SQUID methodology achieving sub-100 nm resolution and 0.3µΦ0/√Hz sensitivity for BTRS domain imaging
Theoretical analysis predicts distinct magnetic signatures from domain walls, edges, and defects in chiral p-wave superconductors
Field-cooling protocols enable visualization of spontaneous magnetic fields that uniquely characterize opposite chirality domains
Complete experimental design includes sensor calibration, imaging procedures, and domain reconstruction algorithms
Method establishes pathway for characterizing topological superconductors and developing topological quantum devices
Limitations & open questions
Weak signal strength from BTRS domains requires careful optimization of signal-to-noise ratios
Thermal and mechanical stability present significant experimental challenges for nanoSQUID operation
Domain reproducibility in field-cooling procedures may affect consistency of imaging results