Complex sentence: He returned to Cambridge in 1967 as an assistant director of research at the Cavendish Laboratory, where he has been a member of the Theory of Condensed Matter (TCM) Group, a theoretical physics group, for much of his career.
Split into simpler sentences: He returned to Cambridge in 1967 as an assistant director of research at the Cavendish Laboratory. He has been a member of the Theory of Condensed Matter (TCM) Group, a theoretical physics group at the Cavendish Laboratory, for much of his career.