SCREENING OF THE COULOMB INTERACTION IN 2-DIMENSIONAL VARIABLE-RANGE-HOPPING

Citation
Fw. Vankeuls et al., SCREENING OF THE COULOMB INTERACTION IN 2-DIMENSIONAL VARIABLE-RANGE-HOPPING, Physical review. B, Condensed matter, 56(3), 1997, pp. 1161-1169
Citations number
54
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics, Condensed Matter
ISSN journal
0163-1829
Volume
56
Issue
3
Year of publication
1997
Pages
1161 - 1169
Database
ISI
SICI code
0163-1829(1997)56:3<1161:SOTCII>2.0.ZU;2-J
Abstract
A Coulomb gap in the density of states is inferred from variable-range -hopping measurements in two dimensions in a gated GaAs/A1(x)Ga(1-x)As heterostructure. For large hopping lengths the Coulomb interaction is screened by a metallic gate, and a universal crossover to Mott hoppin g at low temperatures is observed. Excellent agreement with theory is achieved by adjusting a single combination of constants associated wit h variable-range hopping. This change in constants is explained by cor related hopping. The Coulomb interaction is not screened by the two-di mensional electron layer.