Electronic Structure of InAs Pyramidal Quantum Dots
The above figure is taken from the front cover of the
February 1998 issue of the MRS Bulletin.
It shows the electronic structure of a 45A high, 90A
base, strained InAs pyramidal quantum dot embedded within GaAs. The
strain-modified potential offsets in a (001) plane through the center
of the pyramid are shown above the atomic structure. They exhibit a
well for both heavy holes and electrons. These are localized within
the pyramid and wetting layer as shown by the blue raised(lowered)
triangle and ridge(trough) respectively.
Isosurface plots of the 4 highest hole states and 4 lowest electron
states, as obtained from pseudopotential calculations are shown on the
left and right. The lowest electron state (CBM) is s-like, while
the next 2 states (CBM+1 and CBM+2) are non-degenerate p-like. From
J. Kim, L.W. Wang, A.J. Williamson and A. Zunger (unpublished). See
also the article by A. Zunger in the MRS Bulletin.
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