Research Interests
Overview
An understanding of the behavior of complex systems underlies many of the modern developments in materials science, biochemistry and other fields. Systems such as biomolecules, condensed phases, catalytic surfaces and active soft mater are a challenge for theory because of the complicated nature and diversity of the phenomena observed. They are difficult to simulate because of the wide range of space and time scales they exhibit.
Within this broad area, research has been carried out on the dynamics of phase transitions and critical phenomena, the dynamics of colloidal suspensions, the kinetic theory of chemical reactions in liquids, non-equilibrium statistical mechanics of liquids and mode coupling theory, mechanisms for the onset of chaos in nonlinear dynamical systems, coupled map lattices, the stochastic theory of chemical rate processes, studies of pattern formation in chemically reacting systems, rare event sampling schemes, the construction of mesoscopic molecular dynamics methods and nonadiabatic quantum-classical dynamics. Current research efforts center on study of chemically powered nanomotors, molecular machines, protein dynamics in crowded environments and quantum dynamics in open systems.
Nanomotors, molecular machines and protein dynamics
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Molecular motions and interactions on small distance and time scales are ultimately responsible for the macroscopic properties and behavior of a system. In order to understand how complex natural systems behave, one must connect processes occurring on very small space and time scales, often involving small numbers of molecules, with those on much longer scales. Mesoscopic dynamical methods are being used to investigate protein dynamics, including specific solvent effects, protein molecular machines that undergo conformational changes driven by chemical energy of binding and unbinding of molecules, and biochemical reactions in crowded cells. A problem in nanotechnology is how to interface nanoscale objects with power sources, which can endow them with a particular type of motion. Chemically powered inorganic nanomotors are being studied to explore this issue. |
Quantum-classical dynamics in open systems
| Nonadiabatic processes, which occur when an open quantum system interacts with its environment giving rise to a breakdown of the Born-Oppenheimer approximation, are prevalent in chemical, physical and biological systems. Examples include the dynamics in the vicinity of conical intersections, energy transfer, and proton and electron transfer processes in chemical and biological systems. Research in this area focuses on the description of such processes from the perspective of quantum-classical dynamics where the environment to which the quantum subsystem of interest is coupled may be treated classically to a good approximation. |
