SimOS: A Python Framework for Simulations of Optically Addressable Spins

Abstract: We present an open-source simulation framework for optically detected magnetic resonance, developed in Python. The framework allows users to construct, manipulate, and evolve multipartite quantum systems that consist of spins and electronic levels. We provide an interface for efficient time-evolution in Lindblad form as well as a framework for facilitating simulation of spatial and generalized stochastic dynamics. Further, symbolic operator construction and propagation is supported for simple model systems making the framework also ideal for use in classroom instruction of magnetic resonance. Designed to be backend-agnostic, the library leverages existing Python libraries as computational backends. We introduce the most important functionality and illustrate the syntax on a series of examples. These include systems such as the nitrogen-vacancy center in diamond and photo-generated spin-correlated radical pairs for which our library offers system-specific sub-modules.