Magnetic Field Dependence of Optical Anisotropy in InxGa1?xAs Quantum Dots

We present a mechanism that gives rise to a strong magnetic field dependence of the optical properties in quantum dots even when the dots are too small to have the orbital wavefunction significantly influenced by the field. For large indium contents x ∼ 1, top valence band levels in InxGa1—xAs quantum dots exhibit strong entanglement of the states of which the envelope wavefunction is characterized by s- and p-type symmetries. Although the optical anisotropy associated with each hole level is nearly independent of the magnetic field, the total anisotropy is enhanced when a level crossing is induced by the field.