Unusually thick metal-insulator domain walls around the Mott point

TL;DR

This paper investigates the structure of thick metal-insulator domain walls near the Mott transition, revealing that magnetic frustration in spin-liquid systems leads to unexpectedly broad interfaces, combining theoretical modeling with experimental insights.

Contribution

It provides a systematic theoretical analysis of fat domain walls around the Mott point, linking their thickness to magnetic frustration effects in spin-liquid Mott systems.

Findings

Thick domain walls are caused by magnetic frustration.

The study uses dynamical mean-field theory for modeling.

Results connect domain wall structure to spin-liquid behavior.

Abstract

Many Mott systems feature a first-order metal-insulator transition at finite temperatures, with an associated phase coexistence region displaying inhomogeneities and local phase separation. Here one typically finds "bubbles" or domains of the respective phases, which are separated by surprisingly thick, or fat, domain walls, as revealed both by imaging experiments and recent theoretical modeling. To gain insight into this unexpected behavior, we perform a systematic model study of the structure of such metal-insulator domain walls around the Mott point, within the dynamical mean-field theory framework. Our study reveals that a mechanism producing such "fat" domain walls can be traced to strong magnetic frustration, which is expected to be a robust feature of "spin-liquid" Mott systems.