Monday, October 7, 2013

Tutorial on effective Hamiltonians for quantum dynamics in functional molecular materials

Today I am giving a seminar in the Theoretical Physics Department of the Stefan Institute. The abstract is below. The slides are here. The most important equation [the general form of the Hamiltonian] is missing (!) because I will write it on the white board and discuss at length. It is included below.

This informal tutorial will introduce some of the key concepts and approaches associated with modelling and understanding quantum dynamical processes in complex molecular materials.
This will provide background and motivation for understanding some of my work [1-4].

1. Examples of functional materials: optically active biomolecules, organic light emitting diodes and solar cells, enzymes, …
2. Examples of dynamical processes: charge separation, proton transfer, exciton transport, …
3. Partition: discrete quantum system + environment (solvent or protein)
4. Form of Model Hamiltonians
5. Diabatic states and potential energy surfaces
6. Example: spin boson model
7. Outstanding questions: quantum coherence, sequential vs. concerted, breakdown of Born-Oppenheimer, ...

[1] J. Gilmore and R.H. McKenzie, J. Phys. Chem. A 112, 2162 (2008).
[2] J. Bothma, J. Gilmore, and R.H. McKenzie, New. J. Phys. 12, 055002 (2010).
[3] S.C. Olsen and R.H. McKenzie, J. Chem. Phys. 130, 184302 (2009).
[4] R.H. McKenzie, Chem. Phys. Lett. 535, 196 (2012).


  1. I'm wondering how general such a Hamiltonian can be, when so much depend on the molecular structure and shape of the involved molecular orbitals.

    1. My experience is that this is very general. Changes in molecular structure will change the number of diabatic states needed and the parameters. But, my claim this is a very general form.

    2. So any intermolecular interaction is added in an additional term in the Hamiltonian?

  2. I'd also like to see the Hamiltonian.

    1. Good point. Sorry!
      I have now included it.