Nk. Patel et al., EXCHANGE-INDUCED AND CORRELATION-INDUCED CHARGE-TRANSFER OBSERVED IN INDEPENDENTLY CONTACTED TRIPLE-QUANTUM-WELL STRUCTURES, Physical review. B, Condensed matter, 53(23), 1996, pp. 15443-15446
There have been predictions that for closely spaced two-dimensional el
ectron gases (2DEG's), charge transfer between the 2DEG's can arise fr
om electron interactions due to exchange and correlation [Ruden and Wu
, Appl. Phys. Lett. 59, 2165 (1991)]. In this study, we are able to de
termine accurately the charge in each of the 2DEG's of a triple-quantu
m-well structure. The results demonstrate that as the charge in one 2D
EG is reduced, by applying a negative gate voltage the adjacent layer
can gain charge; thus charge is effectively transferred between the 2D
EG's. This type of charge transfer cannot be explained by a simple non
interacting model of the structure, but can be modeled by including in
tralayer electron interactions in the form of exchange and correlation
correction terms within the local-density approximation. The inclusio
n of these many-body interaction terms into our model leads to a good
qualitative agreement with the experimental data, confirming that the
origin of the charge transfer is electron interactions.