The gas of interacting excitons in quantum wells is studied. We obtain the Hamiltonian of this gas by the projection of the electron-hole plasma Hamiltonian to exciton states and an expansion in a small density. Matrix elements of the exciton Hamiltonian are rather sensitive to the geometry of the heterostructure. The mean field approximation of the exciton Hamiltonian gives the blue shift and ...

We have found experimentally, that the exciton luminescence rise times in GaAdAlGaAs quantum wells oscillate as a function of incident laser energies. Guided by MonkCarlo simulations we interpret these results as the occurrence of selective LO-phonon assisted exciton formation. In the photoexcitation of semiconductors excitons can be generated either directly with high momentum or by free elect...

Recent work on strong coupling exciton}polariton phenomena in single and coupled microcavities is presented. We describe experiments for single cavities where the strong coupling nature of the excitations manifests itself. It is also shown that coupled cavities enable optically induced coupling between macroscopically separated exciton states to be achieved, and polaritons with strongly anisotr...

Recently, we have derived the changes in the absorption spectrum of an exciton when this exciton is photocreated close to a metal. The resolution of this problem – which has similarities with Fermi edge singularities – has been made possible by the introduction of “exciton diagrams” in which the exciton metal-electron vertex has been essentially guessed. The validity of this procedure relied on...

The multi-exciton description of excitation energy transfer in chromophore complexes and biological light harvesting antenna systems is extended to include the exciton-exciton annihilation processes. To achieve a complete microscopic description the approach is based on intra–chromophore internal conversion processes which leads to non-radiative transitions from higher to lower lying exciton ma...

The photosynthetic apparatus of green sulfur bacteria, the chlorosome, is generally considered as a highly efficient natural light-harvesting system. The efficient exciton transport through chlorosomes toward the reaction centers originates from self-assembly of the bacteriochlorophyll molecules. The aim of the present work is to realize a long exciton diffusion length in an artificial light-ha...