Optical probing of the minigap in InAs/GaSb superlattices

We report large modulations in the far infrared absorption of semimetallic InAs/GaSb superlattices in parallel field. The strong absorption is attributed to direct transitions across the minigap at the point where the electron and hole dispersions anticross. The measured minigap energy is found to be in the range 3-10 meV depending on the structure of the sample. The optical results are compared to parallel field magnetoresistance measurements and also to theory using an 8 band k . p calculation. (C) 1998 Elsevier Science B.V. All rights reserved