Symmetry is attractive to the human eye, and Nature often implements it, for example in the shapes of atoms, flowers and plants. But Nature itself often chooses asymmetric shapes, even when, apparently, it could prefer symmetric configurations. The Jahn-Teller theorem, formulated in 1936, involves precisely a symmetry "breaking" in the shape of molecules, with far reaching implications in the study and development of new materials, including superconductors and magnets. Accordingly, the phenomenon is largely investigated in modern biology, chemistry and physics. The international symposia on the Jahn-Teller effect represent a series of biannual conferences, the first being held in 1976 in Bad Honnef, the latest one in August 2008 in Heidelberg JT2008. They serve the purpose of bringing together active researchers in the field of Jahn-Teller and related vibronic interactions, and stimulate further work by presentations of latest results, joint discussions and exchange of ideas. One highlight in this field is the work of K.A. Mueller who was awarded the 1987 Nobel prize in physics for the discovery of high-Tc superconductivity in compounds where he was precisely investigating the Jahn-Teller effects. These compounds find widespread applications nowadays in medical Magnetic Resonance Imaging equipment.
More than half a century ago Robert S. Mulliken: "What are the electrons in molecules really doing?".
Entering the new millennium, we will ask "What are the nuclei in molecules really doing? (as a result of what the electrons are doing...). The XX conference in Fribourg 2010 will concentrate on the recent developments of theory and experiments about the Jahn-Teller effect, gathering together internationally renown scientists in the field and young researchers in several areas of science.
The main topics are:
- The role of the Jahn-Teller Effect in the Mechanism of Superconductivity
- Vibronic Coupling in Ferroelectrics
- Quantum Chemistry and the Treatment of Orbital Degeneracy
- Cooperative Jahn-Teller Effect and Orbital Ordering
- Conical Intersections
- The interplay between Vibronic and Exchange Interactions
- Structure and Spectroscopy of Jahn-Teller Active Impurity Centres
- Jahn-Teller Polarons
- Advances in Numerical Methods
- Group Theory and its Applications to the Vibronic Coupling Problems