Physical Chemistry Seminar: David Manolopoulos, Oxford University

About the Seminar

Spin dynamics in radical pairs

Radical (and polaron) pair recombination reactions play a role a wide variety of problems, ranging from why the electroluminescence of organic light emitting diodes changes in the presence of an applied magnetic field to how migratory songbirds detect the direction of the Earth's magnetic field. The quantum mechanical Hamiltonian of a radical pair is straightforward to write down, but the resulting Schrödinger equation is extremely difficult to solve exactly for a radical pair containing a realistic number of hyperfine-coupled nuclear spins. We have developed both semiclassical and quantum mechanical methods to overcome this difficulty, derived the quantum master equations that account for radical pair recombination and electron spin relaxation processes, and performed a variety of benchmark radical pair spin dynamics calculations, including a recent exact quantum mechanical calculation of the spin dynamics of a carotenoid-porphyrin-fullerene molecule that the Hore and Timmel groups have shown to provide a "proof of principle" for the operation of a chemical compass. This talk will review some of the highlights of our work in this area, starting with the problem that first motivated us to work on radical pairs and ending with a demonstration that the problem has now been solved.

About the Speaker

David Manolopoulos obtained a BA in Natural Sciences from Cambridge in 1984, and a PhD under the supervision of David Clary in 1988. After completing postdoctoral work at the University of Texas at Austin, he moved to a lectureship in Physical Chemistry at the University of Nottingham in 1990, and to a lectureship in Physical and Theoretical Chemistry at Oxford in 1995. He became a Professor of Theoretical Chemistry in 2005.

David’s research in chemical dynamics has been recognised by several awards, including the Marlow Medal of the Royal Society of Chemistry (1995), the Corday-Morgan Medal (1997), the Chemical Dynamics Award (2009), and the Annual Prize of the International Academy of Quantum Molecular Science (2000). He was elected a Fellow of Royal Society in 2011 and a Member of the International Academy of Quantum Molecular Science in 2013. He has been an Associate Editor of the Journal of Chemical Physics since 2008, and a Deputy Editor since 2015. 

Host: Grant Rotskoff