We ¯nd in 2D electron layers in quantum transistors that the interplay between the electron correlations and their interactions with defects in the semiconductor substrate generates a continuous localisation{delocalisation transition for intermediate electron densities (5 <» rs <» 9). We distinguish this transition from the discontinuous metal{insulator transition which is observed at lower electron densities (rs >» 10). The approach we use is based on the behaviour of electrons at low densities. We take into account the interactions between electrons and also their interactions with disorder. We determine a zero temperature phase diagram of localised and delocalised states as a function of electron and impurity densities. The phase boundary of the continuous transition is determined by the localisation length of the electrons.
Continuous localisation-delocalisation transition at intermediate electron densities
NEILSON, DAVID;
1999-01-01
Abstract
We ¯nd in 2D electron layers in quantum transistors that the interplay between the electron correlations and their interactions with defects in the semiconductor substrate generates a continuous localisation{delocalisation transition for intermediate electron densities (5 <» rs <» 9). We distinguish this transition from the discontinuous metal{insulator transition which is observed at lower electron densities (rs >» 10). The approach we use is based on the behaviour of electrons at low densities. We take into account the interactions between electrons and also their interactions with disorder. We determine a zero temperature phase diagram of localised and delocalised states as a function of electron and impurity densities. The phase boundary of the continuous transition is determined by the localisation length of the electrons.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
