Notes on Software Engineering

Abstract

This chapter contains practical implementation and parallelisation advice for large-scale numerical spin dynamics simulation software, dealing in particular with the challenge of simulating simultaneous spatial and spin dynamics. The principal difference with DMRG-like methods is that state vector compression is rarely a good idea for long-range dissipative dynamics of real-life spin systems—a halfway point is advocated instead, wherein the evolution generator is compressed but the state vector is not. Miscellaneous wisdom on the logistical minutiae of spin dynamics simulations (efficient norm estimation, recycling of expensive matrix functions, semi-analytical methods, etc.) is given, as well as a discussion of parallelisation modalities.