Graduate School in Nonlinear Science

Sponsored by the Danish Research Academy

MIDIT                               OFD                           CATS
Modelling, Nonlinear Dynamics       Optics and Fluid Dynamics     Chaos and Turbulence Studies
and Irreversible Thermodynamics     Risø National Laboratory      Niels Bohr Institute and 
Technical University of Denmark     Building 128                  Department of Chemistry
Building 321                        P.O. Box 49                   University of Copenhagen 
DK-2800 Lyngby                      DK-4000 Roskilde              DK-2100 Copenhagen Ø
Denmark                             Denmark                       Denmark


by M. Saffman
OFD, Risø
Roskilde, Denmark

Thursday April 15, 1999, 10:00 h
at Meeting Room, Physics Department, Bld. 108.
Risø National Laboratory, Roskilde

Abstract: In the 18th february issue of Nature a group at Harvard demonstrated light speeds of only 17 metres/second in an ultracold atomic gas. The physical principles behind the Harvard experiments date back to theoretical work from the late 80's on "electromagnetically induced transparency", "lasing without inversion" and other remarkable effects that fall under the heading of "quantum interference" in multilevel atoms.

I will give a pedagogical introduction to the topic, using as simple a theoretical description as possible, and then review earlier experimental results, as well as the recent work at Harvard. Prospects for routinely creating giant optical nonlinearities will be mentioned.