Unconventional Metallic State in Two Dimensional System With Broken Inversion Symmetry

TL;DR

This paper introduces a model explaining the enhanced metallic conduction and metal-insulator transition in 2D electron systems, emphasizing the roles of Coulomb and spin-orbit interactions amplified by broken inversion symmetry.

Contribution

It provides a theoretical explanation for recent experimental observations in high-mobility Si-MOS structures involving broken inversion symmetry.

Findings

Enhanced metallic conduction at low temperatures explained by the model.

Occurrence of metal-insulator transition linked to Coulomb and spin-orbit interactions.

Broken inversion symmetry significantly amplifies spin-orbit effects.

Abstract

We present a model that explains two phenomena, recently observed in high-mobility Si-MOS structures: (i) the strong enhancement of metallic conduction at low temperatures, T<2 K, and (ii) the occurrence of the metal-insulator transition in 2D electron system. Both effects are prescribed to the Coulomb and spin-orbit interaction; the latter is anomalously enhanced by the broken inversion symmetry of the confining potential well.