Zener tunneling effect of excitons in shallow superlattices - art. no. 085307

The Zener effect in the optical absorption of shallow superlattices is stud ied theoretically and experimentally. The comparison between the Kane appro ximation, which is the widely accepted picture so far, and a numerical calc ulation including all subbands, provides clear evidence for the Zener effec t. The experimental spectra are in good agreement with the theory. The meas ured line broadening as a function of the electric field behaves as predict ed by the Zener theory, and is of the same order of magnitude as calculated from the sample parameters. We also suggest absorption measurements in a m agnetic field in growth direction, which would provide an even clearer demo nstration for the transition between discrete transitions and the continuum due to Zener tunneling.