The research efforts of the Atomic and Molecular Physics group are concerned primarily with various aspects of the interaction of electromagnetic radiation with matter, as well as atomic and molecular collisions. With the advent of high power tunable laser spectroscopy, research in this field is rapidly expanding in connection with energy and chemical applications.
Included in the Atomic and Molecular group are Professors Tu-nan Chang, Robin Shakeshaft, and Howard Taylor.
Professor Tu-nan Chang's research activities are concerned primarily with the developments of general theoretical formalism as well as their applications to atomic and molecular systems. Aside from his continuous efforts on mathematical developments related to general atomic structure theory, the main objectives of his work are to develop, as appropriate, new theoretical approaches and to extend the available many-body theoretical methods with emphasis on the physical interpretation of various many-body effects in atomic and molecular processes. On the application side, many static and dynamic properties of atomic and molecular systems, in particular those related to astrophysical interests, energy development related processes and laser development, are being studied. These include studies of i) atomic transitions dominated by many electron interactions in atoms and ions, ii) single and multi-photon processes, iii) photoionization dominated by highly correlated excited states, iv) autoionization in metal vapors, v) atomic transitions involving inner-shell electrons, and vi) energy levels, fine structures, oscillator strengths, and radiative lifetimes.
Professor Robin Shakeshaft is primarily interested in the theory of atomic processes in intense laser radiation. At present he is developing theoretical methods for calculating cross sections for high-order multiphoton processes, including ionization, harmonic generation, Raman scattering, and laser-assisted electron-atom scattering, with emphasis on effects arising from the nonperturbative nature of the field, from electron correlation in multielectron systems, and, when the radiation consists of two harmonics, from the relative phase of the two fields. Attention is given to both the mathematical and physical structures underlying a problem, so as to develop powerful analytical and numerical tools.
Professor Howard Taylor has worked in several fields of atomic, molecular and chemical physics for the last ten years. The approaches to problems have been theoretical, but his group spends much time in close contact with experimentalists. The foremost interest at this time is in the field of nonlinear processes in Quantum and Classical Mechanics.