Degree of circular polarization in II–VI diluted magnetic semiconductor quantum dots

Degree of circular polarization (DCP) in II–VI diluted magnetic semiconductor quantum dots (QDs) has been studied analytically. Energy levels have been calculated using Luttinger–Kohn Hamiltonian and effective mass approximation. Effects due to application of externa magnetic field have been investigated, followed by calculation of transition dipole moment and DCP. Numerical estimates made for Mn-doped CdSe/ZnSe QDs show that DCP in undoped QDs is negligible while transition metal ion doping yields substantial polarization rotation (≈−2.20%≈−2.20%) even at moderate magnetic fields (≈0.5T).

► Electron and hole energies are analytically obtained using Luttinger Hamiltonian in DMS QDs. ► The exchange and Zeeman energy splitting are found to counterbalance each other. ► Transition dipole moment and degree of circular polarization (DCP) is calculated for the same system. ► The results are applied to Mn-doped CdSe/ZnSe QDs showing vanishingly small DCP for undoped QDs. ► In doped QDs substantial polarization rotation can be achieved at moderately small magnetic fields.