Quantum Mott Transition and Superconductivity

TL;DR

This paper explores the quantum criticality of the Mott transition, revealing its connection to unconventional superconductivity and non-Fermi-liquid behavior in correlated electron systems.

Contribution

It demonstrates how mode-coupling theory explains high-temperature d-wave superconductivity near the Mott transition.

Findings

Quantum criticality suppresses the Mott transition temperature.

Density fluctuations support d-wave superconductivity at ~100 K.

Non-Fermi-liquid properties emerge near the quantum critical point.

Abstract

The gas-liquid transition is a first-order transition terminating at a finite-temperature critical point with diverging density fluctuations. Mott transition, a metal-insulator transition driven by Coulomb repulsion between electrons, has been identified with this textbook transition. However, the critical temperature of the Mott transition can be suppressed, resulting in unusual quantum criticality. It accounts for non-Fermi-liquid-like properties, and strongly momentum dependent quasiparticles as in many materials near the Mott insulator. Among all, the mode-coupling theory of the density fluctuations supports d-wave superconductivity at the order of a hundred Kelvin for relevant parameters of the copper oxide superconductors.