My research deals with the structure and dynamics of condensed phase systems, and in particular, in the theory of time-dependent phenomena in liquids, supercritical fluids, crystalline and amorphous solids, on surfaces, and in proteins. We typically use the methods of classical and quantum non-equilibrium statistical mechanics to investigate these phenomena.
Experimentally, one important avenue for determining the structure and dynamics of condensed matter involves vibrational and optical spectroscopy. Typically, such spectroscopy contains information about local molecular environments, whose extraction, however, usually requires theoretical models and their solutions. For some time we have been developing theoretical models for molecular spectroscopy in crystals, amorphous solids, liquids, and in proteins, and have performed calculations on specific systems for comparison with a number of different types of experiments. Examples include: single-molecule spectroscopy in crystals, glasses and biopolymers, hole-burning spectroscopy in proteins, and conventional and ultrafast vibrational spectroscopy in liquids, supercritical fluids and proteins, and at interfaces.
Relaxation processes are important for the understanding of chemical reaction dynamics, electron transfer reactions, NMR spectroscopy, solid-state laser design, and many other fields. We been involved with developing theories of relaxation processes in condensed phases. Our interests range from fundamental issues in non-equilibrium quantum statistical mechanics, to calculations of multi-phonon relaxation in crystals, and to theories of vibrational energy relaxation in liquids.