Lecture R. van Leeuwen
|19 november 2004||FWN-Building 5118.-156, Nijenborgh 4, 9747 AG, Groningen|
|Speaker:||Dr. R. van Leeuwen|
|Affiliation:||Theoretical Chemistry, FWN, Rijksuniversiteit Groningen|
|Title:||New approaches to nonequilibrium phenomena in quantum chemistry|
|Date:||Fri Nov 19, 2004|
|Telephone:||+31 50 363 4369|
The recent developments in nanoscience have opened up many new areas of application and posed new challenges for the quantum chemist, especially regarding the nonequilibrum phenomena of excitation, relaxation and transport in molecules, solids and nanodevices. The task of the quantum chemist is to explain, predict and give detailed insight into these phenomena and to develop methods to describe them. These phenomena include electron transport through single molecules, molecular switching, short laser pulse excitation and exciton transport in molecules and the relaxation of these excitation due to electron-electron interactions and coupling to molecular vibrations. A full theoretical understanding of these nonequilibrium phenomena is a great theoretical challenge since, for instance in molecular transport, virtually nothing is known about the importance of electron-electron correlation and couplings between electronic and nuclear motion. These interactions cause dissipation and lead to the steady current that is measured in break junction experiments. Also little is known about the detailed electron and electron-nuclear dynamics in molecules and solids excited by short and intense laser pulses and which determines the (non)linear optical properties of these materials. To study these phenomena from first principles the traditional toolbox of the quantum chemist is clearly insufficient and new methods must be developed to attack these highly nonlinear nonequilibrium phenomena.
In this presentation I will present two new methods that can deal with these phenomena: the nonequilibrium Green function method and time-dependent density-functional theory. I will further discuss a new method to deal with electron-nuclear dynamics. I will demonstrate clearly why these methods can cope with difficult nonequilibrium phenomena and I will illustrate the methods with a number of physical examples.
|Laatst gewijzigd:||22 oktober 2012 14:31|