Laudatio

For his original and outstanding contributions to the role of chaos in realistic atomic systems

Dr. Dominique Delande

has been awarded the Martin-Gutzwiller-Fellowship 2000
of the Max Planck Institute for the Physics of Complex Systems.

In a seminal Physical Review Letter from 1986, Dr. Delande demonstrated the signatures of chaos by analyzing the statistical properties of the energy levels of the hydrogen atom in a magnetic field.
Besides important contributions on the spectral statistics of diamagnetic hydrogen and alkali atoms, Delande showed in 1993 that 'ghost orbits' contribute to the experimentally observed spectrum before they are born as real orbits at a classical bifurcation point, under variation of the scaled energy. These corrections to the semiclassical trace formula extend Gutzwiller's prediction, in the vicinity of bifurcations.
Dr. Delande's research reflects unique skills, in numerical as well as analytical methods. The former skills have enabled him to calculate theoretically the benchmark spectra necessary for the extraction of chaotic signatures. He was also among the first to develop a code for the calculation of photo-absorption in Helium, into very high lying resonant states (together with Wintgen in 1991).
On the analytical side a deep insight into the group theoretical properties of the Coulomb problem with external fields led him to suggest a new and efficient method for the experimental preparation of circular Rydberg states through adiabatic switching of crossed magnetic and electric fields (1988), which has become one of two standard techniques in the laboratory today.

Dr. Delande's talk on September 11, 2000

"Beyond periodic orbit theory and random matrix theory in atomic physics"

http://www.mpipks-dresden.mpg.de/pages/forschung/forschung_gutzwiller.html