Interatomic Coulombic Decay and its exploration by short, intense and coherent light pulses
Date | Di, 13.05.2014 | |
Time | 16.45 | |
Speaker | Prof. Dr. Lorenz Cederbaum, Institute of Physical Chemistry, University of Heidelberg, Germany | |
Location | ETH Zurich, Hönggerberg Campus, HCI J3 | |
Program | Following the lecture there will be an “Apéro” in HCI J 243, where you are most welcome to join. Abstract: How does a microscopic system like an atom or a small molecule get rid of the excess electronic energy it has acquired, for instance, by absorbing a photon? If this microscopic system is isolated, the issue has been much investigated and the answer to this question is more or less well known. But what happens if our system has neighbors as is usually the case in nature or in the laboratory? In a human society, if our stress is large, we would like to pass it over to our neighbors. Indeed, this is in brief what happens also to the sufficiently excited microscopic system. A new mechanism of energy transfer has been theoretically predicted and verified in several exciting experiments. This mechanism seems to prevail “everywhere” from the extreme quantum system of the He dimer to water and even to quantum dots. The transfer is ultrafast and typically dominates other relaxation pathways. To exploit the high intensity of laser radiation available today, we also propose to select frequencies at which single-photon absorption is of too low energy and two or more photons are needed to produce states of an atom that can undergo interatomic Coulombic decay (ICD) with its neighbors. The study can provide a hint how the energy deposited by a FEL on one site in a medium can be transferred fast to the surrounding. |