 While at Lockheed Sachs began developing with Solomon Schwebel a field theory of quantum electrodynamics that included broken symmetries that did not require recourse to renormalization or perturbation techniques – the "Schwebel-Sachs" model.During this time Sachs was also employed as Assistant Professor of Physics at San Jose State College.In 1961 he became a Research Professor at McGill University; this was followed by a post as Associate Professor of Physics at Boston University (1962–1966).