We present mrfmsim, an open-source Python package that facilitates the design, simulation, and analysis of magnetic resonance force microscopy (MRFM) experiments. MRFM is a scanning-probe technique that detects magnetic resonance from nanoscale ensembles of nuclear or electron spins with a force sensor. Because MRFM experiments are complex and operate at sensitivity limits, numerical simulation is essential for designing experiments and estimating per-spin sensitivity and imaging resolution from measured signals. In this paper, we highlight the challenges of developing MRFM simulations and show that software designed to simulate specific experiments only in a rapidly evolving experimental field can yield erroneous results. The mrfmsim package addresses these challenges by supporting post-definition customization without rewriting the internal model and by employing a plugin system for extending functionality. We show that the package's modular, extendable, and readable architecture improves reproducibility and accelerates development.
@article{arxiv.2602.23337,
title = {mrfmsim: A modular, extendable, and readable simulation package for magnetic resonance force microscopy experiments},
author = {Peter Sun and Corinne E. Isaac and Michael C. Boucher and Eric W. Moore and Zhen Wang and John A. Marohn},
journal= {arXiv preprint arXiv:2602.23337},
year = {2026}
}