Oberli, D. Y. and Byszewski, M. and Chalupar, B. and Pelucchi, E. and Rudra, A. and Kapon, E.

2009

Physical Review B

Coulomb correlations of charged excitons in semiconductor quantum dots

Validated

()

80

16

The emission pattern of charged excitons in a semiconductor quantum dot (QD) is composed of a quadruplet of linearly polarized lines when a magnetic field is applied in a Voigt configuration. The orientation of the linear polarization of exciton emission is controlled by the orientation of the magnetic field in QDs with C(3v) symmetry while for QDs with C(2v) symmetry it is not. We demonstrate that the g factor of holes is very sensitive to the dot shape asymmetry but that of electrons is not. By comparing the effective g factors obtained for the neutral and charged excitons in the same quantum dot, we uncover the role of Coulomb correlations in these excitonic states. We show that the C(3v) symmetry of pyramidal QDs makes them ideal candidates for implementing all-optical many-qubits gates based on electron spin as a quantum bit.