Young, R J and Stevenson, R M and Shields, A J and Atkinson, P and Cooper, K and Ritchie, D A and Groom, K M and Tartakovskii, A I and Skolnick, M S (2005) Inversion of exciton level splitting in quantum dots. Physical review B, 72 (11): 113305. -. ISSN 1098-0121
Full text not available from this repository.Abstract
The demonstration of degeneracy of exciton spin states is an important step toward the production of entangled photon pairs from the biexciton cascade. We measure the fine structure of exciton and biexciton states for a large number of single InAs quantum dots in a GaAs matrix; the energetic splitting of the horizontally and vertically polarized components of the exciton doublet is shown to decrease as the exciton confinement decreases, crucially passing through zero and changing sign. Thermal annealing is shown to reduce the exciton confinement, thereby increasing the number of dots with splitting close to zero.