Intersubband transitions in InAs GaSb semimetallic superlattices

We report parallel magnetic-field-activated intersubband absorption in InAs /GaSb semimetallic superlattices. The samples were studied in the Voigt con figuration enabling normal-incidence excitation of the intersubband transit ion. For samples with narrow wells, the small absorption coefficient meant that an alternative waveguide configuration was used, again with magnetic f ield applied parallel to the superlattice layers. In this latter configurat ion we see further activation of the intersubband resonance by the parallel field as well as new transitions to higher subbands, The intersubband ener gy and absorption characteristics are studied over a large range of well wi dths and compared with results from eight-band k.p calculations. [S0163-182 9(99)03416-5].