Comparison of the k center dot p and direct diagonalization approaches to the electronic structure of InAs/GaAs quantum dots

We present a comparison of the 8-band k.p and empirical pseudopotential app roaches to describing the electronic structure of pyramidal InAs/GaAs self- assembled quantum dots. We find a generally good agreement between the two methods. The most significant differences found in the k.p calculation are (i) a reduced splitting of the electron p states (3 vs 24 meV), (ii) an inc orrect in-plane polarization ratio for electron-hole dipole transitions (0. 97 vs 1.24), and (iii) an over confinement of both electron (48 meV) and ho le states (52 meV), resulting in a band gap error of 100 meV. We introduce a "linear combination of bulk bands" technique which produces results simil ar to a full direct diagonalization pseudopotential calculation, at a cost similar to the k.p method. (C) 2000 American Institute of Physics. [S0003-6 951(00)01903-3].