Observation of a hybridization gap in cyclotron resonance spectra of semimetallic InAs/GaSb quantum wells

Splitting of the cyclotron resonance (CR) line is observed in the electron CR spectra of InAs/GaSb heterostructures containing tunneling-coupled electron and hole layers. This splitting is interpreted to be a manifestation of a hybridization gap arising as a result of anticrossing of the Landau levels of electrons and holes when their wave functions overlap. The energy splitting of the CR lines is correlated with the magnitude of the overlap and agrees with theoretical estimates of the hybridization gap width. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 4, 313–317 (25 February 1999)