Observation of semiconductor-semimetal transition in InAs-GaSb superlattices

The semiconductor-semimetal transition in InAs-GaSb superlattices is observed at a layer thickness in the vicinity of 100 Å. The transition manifests itself in an increase in the measured carrier concentration as a result of electron transfer from GaSb to InAs when ground subbands of electrons and heavy holes cross each other. Shubnikov-de Haas measurements confirm the carrier enhancement in the semimetallic state.