Pressure-Tuned Resonance Raman Scattering in InAs/GaSb Superlattices

We have performed a pressuretuned resonance Raman scattering study in short-period GaSb/InAs SLs in the region of E1 and E1 + Δ1 in GaSb. Resonance profiles for polarized Raman scattering by both LO and elastic interface modes reveal two electronic transitions with two different types of Frohlich-interaction-induced scattering. The LO resonance at the E1 gap displays strong interference and we attribute it to intrinsic intrasubband Frohlich scattering, which is dipole allowed due to the difference in the degree of localization of the electron and hole wave functions. A new resonance enhancement peak, not present in the bulk, has been observed in between the E1 and E1 + Δ1 gaps of GaSb. This resonance appears to be dominated by extrinsic Frohlich scattering.