Comparing pseudopotential predictions for InAs/GaSb superlattices

Abstract

For several years, we have been accurately calculating the electronic structure of superlattices using a solution technique based on the empirical pseudopotential method. In our method for forming the superlattice pseudopotential, the critical assumption is that the heterointerface charges are redistributed, making each constituent layer in the superlattice as bulklike as possible. Here, we demonstrate that our technique for forming the superlattice pseudopotential is fundamentally different from the atomistic pseudopotential approaches that use a superposition of atomic pseudopotentials to represent the superlattice. We then present several applications of our method to InAs-GaSb type-II superlattices and, where possible, we compare our results to those calculated with an effective mass method, as well as to atomistic pseudopotential methods. In all of these comparisons, our method provides excellent agreement with the measured data.