From basic properties to the Mott design of correlated delafossites

TL;DR

This paper reviews the electronic properties of layered delafossite oxides, highlighting how inter-layer coupling influences their correlated electronic states and opens new avenues for designing materials with exotic Mott-related phenomena.

Contribution

It introduces the concept of layer-entangled electronic states in delafossites and explores their potential for novel correlated electronic phases and materials design.

Findings

Layer-entangled electronic states deviate from standard classifications.

Manipulation of Hidden-Mott physics and correlation-induced semimetallicity.

Emergence of Dirac/flat-band dispersions in a Mott background.

Abstract

The natural-heterostructure concept realized in delafossites highlights these layered oxides. While metallic, band- or Mott-insulating character may be associated with individual layers, inter-layer coupling still plays a decisive role. We review the correlated electronic structure of PdCoO$_2$, PdCrO$_2$ and AgCrO$_2$, showing that layer-entangled electronic states can deviate from standard classifications of interacting systems. This finding opens up possibilities for materials design in a subtle Mott-critical regime. Manipulated Hidden-Mott physics, correlation-induced semimetallicity, or Dirac/flat-band dispersions in a Mott background are emerging features. Together with achievements in the experimental preparation, this inaugurates an exciting research field in the arena of correlated materials.