Weak localization, hole-hole interactions, and the "Metal"-insulator transition in two dimensions
A detailed investigation of the metallic behavior in high-quality GaAs-AlGaAs two-dimensional hole systems reveals the presence of quantum corrections to the resistivity at low temperatures. Despite the low density ( r(s)>10) and high quality of these systems, both weak localization (observed via negative magnetoresistance) and weak hole-hole interactions (giving a correction to the Hall constant) are present in the so-called metallic phase where the resistivity decreases with decreasing temperature. If these quantum corrections persist down to T = 0, the results suggest that even at high r(s) there is no metallic phase in two dimensions.
Simmons
MY
Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 OHE, United Kingdom and Semiconductor Nanofabrication Facility, University of New South Wales, Sydney 2052, Australia.
Hamilton
AR
Pepper
M
Linfield
EH
Rose
PD
Ritchie
DA