S. Zimmermann et al., LATERAL SUPERLATTICES AS VOLTAGE-CONTROLLED TRAPS FOR EXCITONS, Physical review. B, Condensed matter, 56(20), 1997, pp. 13414-13421
We demonstrate the localization of quantum-well excitons in a periodic
array of linear traps using photoluminescence experiments. The excito
nic traps are induced by applying spatially alternating external volta
ges via interdigitated metal gates. The localization originates from t
he periodical modulation of the strength of the quantum-confined Stark
effect in the plane of the quantum well. In our experiments, the trap
depth is easily tuned by the voltages applied to the interdigitated g
ates. Furthermore, we find that a perpendicular magnetic field reduces
the exciton diffusion length. In short-period lateral superlattices,
we observe a magnetic-field-induced stabilization of excitons in the p
resence of strong in-plane electric fields.