| Citation | Distinguished for his studies of interactions between ultracold atoms produced using laser and evaporative cooling as well as for the study of atoms and collision complexes in intense laser fields. In the subject of ultracold atoms he led the development of theories to study the limits to temperatures and densities that can be reached using laser and evaporative cooling. He carried out the first calculations of the excitation spectra of trapped Bose condensed atomic gases that are produced using evaporative cooling. He also showed how to use computational methods to study the way these gases could be used as coherent sources of matter waves. His experimental and theoretical studies of atomic collisions in laser fields have shown how the mechanism of atomic collisions can be probed and sometimes switched in the presence of an intense laser field. His work on the interaction of intense laser fields with atoms has led to new insights into the way one can generate cogerent XUV radiation by upconversion. The theory that he has developed has been ised to model a wide range of experiments. His theory of multi-electron processes in strong fields has shown how electron correlation effects can produce nonsequential ejection of electrons. His eminence in the field has been recognised by the ward of the IoP Thomas Young medal. |