The Mott criterion: So simple and yet so complex

TL;DR

This paper discusses the broad applicability of the Mott criterion to various materials undergoing metal-insulator transitions, emphasizing its relevance beyond traditional semiconductors and highlighting specific cases like V2O3.

Contribution

It demonstrates that the Mott criterion applies to a wide range of materials, including strongly correlated compounds, and reviews the history and current understanding of the Mott transition.

Findings

Mott criterion applies to many materials beyond semiconductors

The criterion is relevant for transition-metal and rare-earth-metal compounds

Special focus on the V2O3 metal-insulator transition

Abstract

September 30, 2015 marks the 110th anniversary of the birth of the famous English physicist N. F. Mott. This article is dedicated to his memory. Here we consider the problem of metal-insulator transition. It is shown that the Mott criterion $a_{B}(n_{c})^{1/3} \approx 0.25$ is applicable not only to heavily doped semiconductors, but also to many other materials and systems, including strongly correlated transition-metal and rare-earth-metal compounds, such as vanadium oxides. A special emphasis is placed to the 'paramagnetic metal - antiferromagnetic insulator' transition in $V_{2}O_{3}$ doped with chromium. In Supplement we also briefly consider the history and state of the art of the Mott transition problem.