Heterostructure interface effects on the far-infrared magneto-optical spectra of InAs/Gasb quantum wells

The electronic and optical properties of InAs/GaSb heterostructures depend on the type of bonding at the interfaces, InSb bonds or GaAs bonds. We have studied cyclotron resonance (CR) in the far-infrared on two samples, each consisting of a single 30 nm InAs quantum well surrounded by thick GaSb barriers. The only intended difference between the samples is the interface bonding type, Ga-As bonds and In-Sb bonds. The CR for the sample with Ga-As interface bonds shows two lines whose positions are determined by nonparabolicity effects, whereas the sample with In-Sb bonds shows multiple lines due to strong cross-interface coupling between the InAs conduction band Landau levels (LLs) and the valence band LLs in GaSb. We find that the CR is a sensitive probe of interface bonding type for such structures.