We explain the experimental observation of only zero-spin biexciton in GaAs quantum wells, contrary to different spin configurations known in bulk crystals. Making use of the exciton Hamiltonian that reduces the four-body biexciton problem to two-exciton problem, we show that the only possible bound state of two excitons is a linear combination of two bright excitons with spins ±1 and two dark excitons with spins ±2. We suggest experiments that can detect the existence of the dark component of the biexciton wave function.
ASJC Scopus subject areas
- Physics and Astronomy (all)