Heterostructures interface effects on the far-infrared magneto-optical spectra of indium arsenide/gallium antimonide quantum wells

Heterostructures based on InAs/GaSb have been of considerable interest because of their type-II broken-gap band alignment. This gives rise to interesting and unusual electronic properties, such as spatial separation of electrons and holes and cross-interface coupling between InAs conduction band and GaSb valence band. A large range of unique devices have been conceived based on these special properties, e.g., infrared detectors and lasers, resonant interband tunneling diodes (RITDs), and high electron mobility transistors (HEMT). An additional flexibility in engineering these structures comes from the fact that at the InAs/GaSb heterojunction there are two types of interface that can be formed, either Ga-As bonds or In-Sb bonds. We performed FIR magneto-transmission experiments to find the way the interface bonding type affects the electronic properties of InAs/GaSb heterostructures. We found that the cross-interface coupling is stronger for the heterojunctions with In-Sb bonds than for the heterojunctions with Ga-As bonds.