Erik J. Gustafson, Research Institute for Advanced Computer Science, Mountain View

We develop an extension for scalable circuits (SC)-ADAPT-VQE, originally developed by Farrell et al., involving surrogate constructed scalable circuits, that allows for a systematic construction of the ansatz with a truncated operator pool utilizing ancillary classical calculations. This extension to SC-ADAPT-VQE allows for a rigorous variational operator that has increased stability for ansatz structure as the system sizes are increased. Additionally there is an implicit decrease in sampling overhead by a reduction in total size of the ADAPT-VQE operator pool. This can be applied to a wide class of quantum models, ranging from quantum chemistry to high energy and nuclear physics Hamiltonians. As an example, we use it to compute some properties of the Schwinger model and show that our method can be used to accurately extrapolate to the continuum limit.