Coherent back-scattering near the two-dimensional metal-insulator transition

TL;DR

This study investigates how coherent backscattering affects conductivity in low-disorder 2D silicon electron systems near the metal-insulator transition, revealing suppression of localization effects at the transition point.

Contribution

It provides experimental evidence that localization corrections weaken and vanish at the critical density of the transition, challenging traditional localization theories.

Findings

Corrections to conductivity weaken near the transition

Localization effects are suppressed at the critical density

Backscattering corrections vanish at the transition point

Abstract

We have studied corrections to conductivity due to the coherent backscattering in low-disordered two-dimensional electron systems in silicon for a range of electron densities including the vicinity of the metal-insulator transition, where the dramatic increase of the spin susceptibility has been observed earlier. We show that the corrections, which exist deeper in the metallic phase, weaken upon approaching to the transition and practically vanish at the critical density, thus suggesting that the localization is suppressed near and at the transition even in zero field.