Meta-Percolation and Metal-Insulator Transition in Two Dimensions

TL;DR

This paper introduces the concept of meta-percolation as a novel mechanism for the metal-insulator transition in two-dimensional systems, challenging traditional localization theory and connecting to recent experimental observations.

Contribution

It proposes a new type of percolation, meta-percolation, explaining 2D metal-insulator transitions at finite temperatures where phase coherence length is finite.

Findings

Identification of meta-percolation as a cause of 2D MIT

Relevance to recent experimental observations of 2D MIT

Challenging the traditional localization theory in 2D systems

Abstract

According to the scaling theory of localization, all quantum electronic states are localized in two-dimensional (2D) systems. One consequence of the theory is that there is no quantum percolation transition in 2D. However, in a real system at a finite temperature, electron phase coherent length is finite and the system is between quantum and classical. We find, in such a 2D system, a metal-insulator transition (MIT) caused by a novel type of percolation, meta-percolation. The relevance to recently observed 2D MIT is also discussed.