Phase separation in doped Mott insulators

TL;DR

This paper presents a thermodynamic framework for understanding phase separation in doped Mott insulators, supported by electronic structure calculations that match experimental data, and predicts a percolative transition with Coulomb frustration.

Contribution

It introduces a simple thermodynamic argument for phase separation in doping-driven Mott transitions and applies electronic structure calculations to titanates, aligning theory with experiments.

Findings

Critical dopings for Mott transition computed and match experiments

Transition is predicted to be percolative

Transition should exhibit Coulomb frustration

Abstract

Motivated by the commonplace observation of Mott insulators away from integer filling, we construct a simple thermodynamic argument for phase separation in first-order doping-driven Mott transitions. We show how to compute the critical dopings required to drive the Mott transition using electronic structure calculations for the titanate family of perovskites, finding good agreement with experiment. The theory predicts the transition is percolative and should exhibit Coulomb frustration.