title: Polaritonic stop-band transparency via exciton-biexciton coupling in CuCl.
abstract: Radiation is almost completely reflected within the exciton-polariton stop band of a semiconductor, as in the typical case of CuCl. We predict, however, that a coherently driven exciton-biexciton transition allows for the propagation of a probe light beam within the stop band. The phenomenon is reminiscent of electromagnetically induced transparency effects occurring in three-level atomic systems, except that it here involves delocalized electronic excitations in a crystalline structure via a frequency and wave-vector selective polaritonic mechanism. A well-developed transparency, favored by the narrow linewidth of the biexciton, is established within the stop band where a probe pulse may propagate with significant delays. The transparency window can be controlled via the pump beam detuning and intensity.
authors.affiliation: Department of Physics, Purdue University, West Lafayette, Indiana 47907-1396, USA.
authors.forename: S
authors.initials: S
authors.lastname: Chesi
authors.forename: M
authors.initials: M
authors.lastname: Artoni
authors.forename: G C
authors.initials: GC
authors.lastname: La Rocca
authors.forename: F
authors.initials: F
authors.lastname: Bassani
authors.forename: A
authors.initials: A
authors.lastname: Mysyrowicz