Quantum corrections to conductivity: from weak to strong localization

Minkov, G. M.; Rut, O. E.; Germanenko, A. V.; Sherstobitov, A. A.; Zvonkov, B. N.; Uskova, E. A.; Birukov, A. A.

Quantum corrections to conductivity: from weak to strong localization

Authors

Description

Results of detailed investigations of the conductivity and Hall effect in gated single quantum well GaAs/InGaAs/GaAs heterostructures with two-dimensional electron gas are presented. A successive analysis of the data has shown that the conductivity is diffusive for $k_F l=25-2$ and behaves like diffusive one for $k_F l=2-0.5$ down to the temperature T=0.4 K. It has been therewith found that the quantum corrections are not small at low temperature when $k_F l\simeq 1$. They are close in magnitude to the Drude conductivity so that the conductivity $σ$ becomes significantly less than $e^{2}/h$ (the minimal $σ$ value achieved in our experiment is about $3\times 10^{-8}Ω^{-1}$ at $k_Fl\simeq 0.5$ and $T=0.46$ K). We conclude that the temperature and magnetic field dependences of conductivity in whole $k_Fl$ range are due to changes of quantum corrections.
RevTex 4.0, 10 figures, 7 two-column pages