BAND NONPARABOLICITY AND 3-DIMENSIONAL ASPECTS IN QUANTUM DOTS ON INSB

Quantum dots with high lateral quantization energies are created on In Sb by means of a perforated Schottky gate. With a gate voltage the lat eral quantization energies can be tuned and approach values up to home ga0BAR almost-equal-to 25 meV, which is comparable to the subband sepa rations connected with the vertical motion in the corresponding quasi- two-dimensional electron system. By far-infrared spectroscopy, we obse rve the two fundamental modes omega+/- in a magnetic field and verify the predicted polarization selection rules. The measured transition en ergies are described by employing a realistic three-dimensional model potential and taking into account the conduction band nonparabolicity of InSb and the resulting coupling of the vertical subbands.