Mott Criticality as the Confinement Transition of a Pseudogap-Mott Metal

TL;DR

This paper develops a theoretical model connecting the pseudogap phase in doped Mott insulators to a confinement transition, revealing a non-Fermi liquid state that transitions into a Mott insulator.

Contribution

It introduces a renormalization-based lattice model capturing the pseudogap phase and its continuous transition to a Mott insulator, emphasizing confinement and long-range entanglement.

Findings

Identification of a non-Fermi liquid pseudogap phase with nodal arcs and gapped antinodal regions.

Demonstration of a continuous transition from the pseudogap phase to a Mott insulator via confinement.

Revealing the pseudogap as a long-range entangled quantum phase.

Abstract

The phenomenon of Mott insulation involves the localization of itinerant electrons due to strong local repulsion. Upon doping, a pseudogap (PG) phase emerges - marked by selective gapping of the Fermi surface without conventional symmetry breaking in spin or charge channels. A key challenge is understanding how quasiparticle breakdown in the Fermi liquid gives rise to this enigmatic state, and how it connects to both the Mott insulating and superconducting phases. Here, we develop a renormalization-based construction of strongly correlated lattice models that captures the emergence of the pseudogap phase and its transition to a Mott insulator. Applying a many-body tiling scheme to the fixed-point impurity model uncovers a lattice model with electron interactions and Kondo physics. At half-filling, the interplay between Kondo screening and bath charge fluctuations in the impurity model leads to Fermi liquid breakdown. This reveals a pseudogap phase characterized by a non-Fermi liquid (the Mott metal) residing on nodal arcs, gapped antinodal regions of the Fermi surface, and an anomalous scaling of the electronic scattering rate with frequency. The eventual confinement of holon-doublon excitations of this exotic metal obtains a continuous transition into the Mott insulator. Our results identify the pseudogap as a distinct long-range entangled quantum phase, and offer a new route to Mott criticality beyond the paradigm of local quantum criticality.