- 2015-date: Lucasian Professor of Mathematics and Royal Society Research Professor
- 2007-2015: Professor of Natural Philosophy and Royal Society Research Professor, University of Edinburgh
- 1995-2007: Professor of Natural Philosophy, School of Physics and Astronomy, University of Edinburgh
- 1992-1995: University Lecturer, Cavendish Laboratory, Cambridge
- 1989-1992: University Assistant Lecturer, Cavendish Laboratory, Cambridge
- 1988-1989: Royal Society University Research Fellow, Cavendish Laboratory, Cambridge
- 1985-1995: Junior Research Fellow (1985-1989), Teaching Fellow (1990-1995), Trinity College Cambridge