SOTtools¶
Warning
SOTtools is under active development — the API may change between minor versions.
SQUID-based microscopy (SOT, scanning SQUID) is a powerful tool for locally imaging current distributions by mapping their magnetic fields. Interpreting these maps, however, is difficult: the SQUID singles out one particular component of the magnetic field, and inverting these maps back to a current distribution is a non-trivial problem.
SOTtools is a Python toolkit for modeling and inverting SOT measurements. It provides:
FEM mesh generation and current distribution simulation on arbitrarily shaped samples
Forward models to compute SQUID signal maps from current distributions
Inverse solvers to reconstruct current distributions from SQUID maps
The unique feature of SOTtools is that it is sample-aware: it natively accounts for 1D and 2D sample boundaries and confines all currents to the physical sample geometry.
These inversions are made possible by implementing all forward models in PyTorch, enabling automatic differentiation. The user-facing API, however, is fully NumPy-based, following the conventions of scientific Python.
Originally, SOTtools was developed for and used in Rog, Blom et al., arXiv:2606.20157.