Pressure Dependence of Band Offsets in an InAs-GaSb Superlattice

Using magneto-optical methods, we have measured the pressure dependence of the energy difference between subbands in an InAs-GaSb superlattice associated with the GaSb valence and the InAs conduction bands, respectively. The experimental results allow a determination of the pressure dependence of the energy separation between the InAs conduction band and the GaSb valence band which is found to decrease at a rate of 5.8 meV/kbar. This result shows that both the conduction- and the valence-band offsets are pressure dependent. Therefore these experiments constitute a critical test for different theories of band lineup.