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Hopping conductivity in heavily doped n-type GaAs layers in the quantum Hall effect regime

S. S. Murzin·M. Weiss·A. G. M. Jansen·K. Eberl
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Abstract

We investigate the magnetoresistance of epitaxially grown, heavily doped n-type GaAs layers with thickness (40-50 nm) larger than the electronic mean free path (23 nm). The temperature dependence of the dissipative resistance R_{xx} in the quantum Hall effect regime can be well described by a hopping law (R_{xx} \propto exp{-(T_0/T)^p}) with p=0.6. We discuss this result in terms of variable range hopping in a Coulomb gap together with a dependence of the electron localization length on the energy in the gap. The value of the exponent p>0.5 shows that electron-electron interactions have to be taken into account in order to explain the occurrence of the quantum Hall effect in these samples, which have a three-dimensional single electron density of states.

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S. S. Murzin, M. Weiss, A. G. M. Jansen, K. Eberl. 2001-06-16. Hopping conductivity in heavily doped n-type GaAs layers in the quantum Hall effect regime. https://doi.org/10.1103/physrevb.64.233309

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