The Transport Mechanism In The Heterostructure GaAs/AlGaAs At Very Low Temperature In The Vicinity Of The Metal Insulator Transition

Asmaa Chakhmane^1,2*, Hassan El Idrissi², Abdelhamid El Kaaouachi³, Mohamed Errai³

¹Pluridisciplinary Research and Innovation Laboratory (LPRI), EMSI Casablanca, (MOROCCO)
²Laboratory EEA&TI, Faculty of Sciences and Technology Mohammedia, University Hassan II Casablanca, Mohammedia, (MOROCCO)
³Physics Department, Faculty of Sciences, University Ibn Zohr, Agadir, (MOROCCO)

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ABSTRACT – DOI : https://dx.doi.org/10.47204/EMSR.1.1.2020.067-073

The objective of this work, is to study the transport mechanism contributing to the low temperature electrical conductivity of a two-dimensional GaAs hole gas in the metal and insulating side of the Metal Insulator Transition, for T less than 1K. We reanalyzed the data obtained by Qiu et al published in [R. L.J. Qiu, X.A.A. Gao, L.N. Pfeiffer and K. W. West, PRL 108, 106404 (2012)]. In insulating systems, the electrical transport in a disordered system occurs by the phenomenon of Variable Range Hopping (VRH), which is widely observed, analyzed in several studies and described by  s = s0exp(-T0/T)^p. In this case, the holes move between localized states while traveling different distances, giving rise to two regimes: the Efros & Shklovskii regime (ES VRH) and the Mott regime (Mott VRH). For the metal samples, we studied the temperature dependence of the resistivity r and its impact on the metallic behavior of the system with high hole densities (when dr/dT > 0), beyond a critical density (psc=0,8×10¹⁰cm^-2). The results were verified graphically and confirmed by the percentage of deviation method.