How to recognize the universal aspects of Mott criticality?

TL;DR

This paper reviews various two-dimensional electronic systems undergoing Mott metal-insulator transitions, highlighting common behaviors and comparing experimental data with theoretical models to identify universal aspects of Mott criticality.

Contribution

It provides a comparative analysis of experimental observations across different 2D systems and discusses how theoretical models can be distinguished based on dielectric response analysis.

Findings

Resistivity maximum on the metallic side vanishes at the transition

DMFT and percolation theories can be distinguished by dielectric response analysis

Universal features of Mott criticality are emerging across diverse 2D systems

Abstract

In this paper we critically discuss several examples of two-dimensional electronic systems displaying interaction-driven metal-insulator transitions of the Mott (or Wigner--Mott) type, including dilute two-dimension electron gases (2DEG) in semiconductors, Mott organic materials, as well as the recently discovered transition-metal dichalcogenide (TMD) moir\'e bilayers. Remarkably similar behavior is found in all these systems, which is starting to paint a robust picture of Mott criticality. Most notable, on the metallic side a resistivity maximum is observed whose temperature scale vanishes at the transition. We compare the available experimental data on these systems to three existing theoretical scenarios: spinon theory, Dynamical Mean Field Theory (DMFT) and percolation theory. We show that the DMFT and percolation pictures for Mott criticality can be distinguished by studying the origins of the resistivity maxima using an analysis of the dielectric response.