Novel electronic states close to Mott transition in low-dimensional and frustrated systems

TL;DR

This paper explores novel electronic states near the Mott transition in low-dimensional and frustrated systems, highlighting phenomena like partial Mott transitions and other unique crossover behaviors in correlated materials.

Contribution

It provides concrete examples of partial Mott transitions and discusses various crossover phenomena in low-dimensional and frustrated correlated systems.

Findings

Partial Mott transition in spinels and triangular systems

Finite clusters transition to itinerant regime before bulk transition

Discussion of spin-Peierls transition and charge disproportionation

Abstract

Recent studies demonstrated that there may appear different novel states in correlated systems close to localized-itinerant crossover. Especially favourable conditions for that are met in low-dimensional and in frustrated systems. In this paper I discuss on concrete examples some of such novel states. In particular, for some spinels and triangular systems there appears a "partial Mott transition", in which first some finite clusters (dimers, trimes, tetramers, heptamers) go over to the itinerant regime, and the real bulk Mott transition occurs only later. Also some other specific possibilities in this crossover regime are shortly discussed, such as spin-Peierls-Peierls transition in TiOCl, spontaneous charge disproportionation in some cases, etc.