Electron-electron interaction with decreasing conductance

Abstract

The contribution of the electron-electron interaction to conductivity is analyzed step by step starting from the high conductivity in gated ${\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}/\mathrm{I}\mathrm{n}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{A}\mathrm{s}/\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}\mathrm{}$ heterostructures with different starting disorders. We demonstrate that the diffusion theory works down to ${k}_{F}l\ensuremath{\simeq}1.5\ensuremath{-}2,$ where ${k}_{F}$ is the Fermi quasimomentum and l is the mean free path. It is shown that the $e\ensuremath{-}e$ interaction gives smaller contribution to the conductivity than the interference independent of the starting disorder, and its role rapidly decreases with decreasing ${k}_{F}l.$