MuSpinSim: spin dynamics calculations for muon science

Abstract

MuSpinSim is a Python software to simulate muon (µSR) experiments. In particular, it simulates the spin dynamics of a system of a muon plus other spins such as electrons and atomic nuclei. MuSpinSim can simulate various common experimental setups used in µSR, such as zero, transverse and longitudinal field experiments; and it can simulate µSR experiments that are resolved in time, field, or temperature. Furthermore, MuSpinSim can account for the effects of hyperfine, dipolar, quadrupolar and Zeeman couplings, as well as simulate quantum systems exchanging energy with the environment with the Lindblad master equation. Finally, MuSpinSim can be used to fit experimental µSR data with simulations that use all of the capabilities described above. In this work, we present the Python package MuSpinSim with all the utilities it provides to facilitate simulations of µSR experiments, and we demonstrate the effectiveness of the method with some chosen example systems.