Degenerate versus semi-degenerate transport in a correlated 2D hole system

Abstract

It has been puzzling that the resistivity of high mobility two-dimensional(2D) carrier systems in semiconductors with low carrier density often exhibits a large increase followed by a decrease when the temperature ($T$) is raised above a characteristic temperature comparable with the Fermi temperature ($T_F$). We find that the metallic 2D hole system (2DHS) in GaAs quantum well (QW) has a linear density ($p$) dependent conductivity, $\sigma \approx e{\mu }^{\ast }(p-p_0)$, in both the degenerate (T<<T_F) and semi-degenerate (T T_F) regimes. The $T$-dependence of $\sigma (p)$ suggests that the metallic conduction (d$\sigma$/d$T<$0) at low $T$ is associated with the increase in ${\mu }^{\ast }$, the effective mobility of itinerant carriers. However, the resistivity decrease in the semi-degenerate regime ($T>T_F$) is originated from the reduced $p_0$, the density of immobile carriers in a two-phase picture.

accepted for publication in Phys. Rev. B

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Cited by in corpus (5)

• Screening and transport in 2D semiconductor systems at low temperatures
• Two-dimensional metal-insulator-transition as a potential fluctuation driven semiclassical transport phenomenon
• Connecting the Reentrant Insulating Phase and the Zero Field Metal-Insulator Transition in a 2D Hole System
• Impact of Short-Range Scattering on the Metallic Transport of Strongly Correlated 2D Holes in GaAs Quantum Wells
• Surprising coincidence of the apparent 2D metal-to-insulator transition data with Fermi-gas based model results