Hubbard bands, Mott transition and deconfinement in strongly correlated systems

TL;DR

This paper explores the deconfinement phases in strongly correlated systems, analyzing the Mott transition, Hubbard subbands, and the influence of spin-liquid states across different dimensions.

Contribution

It introduces a combined approach using Kotliar-Ruckenstein representation and fractionalized spin-liquid concepts to analyze the Mott transition and Hubbard subbands.

Findings

Transition to metallic state involves condensation of a gapless boson mode.

Insulating state spectrum is affected by spinon spin-liquid spectrum.

Dimensionality influences confinement and deconfinement phenomena.

Abstract

The problem of deconfinement phases in strongly correlated systems is discussed. In space-time dimension $d=3+1$, a competition of confinement and Coulomb phases occurs, but in $d=2+1$ the confining phase dominates owing to monopole proliferation, but gapless fermion excitations can change the situation. Combining the Kotliar-Ruckenstein representation and fractionalized spin-liquid deconfinement picture, the Mott transition and Hubbard subbands are treated, general expressions in the case of an arbitrary bare band spectrum being obtained. The transition into a metallic state is determined by condensation of a gapless boson mode. The spectrum picture in the insulating state is considerably influenced by the spinon spin-liquid spectrum and hidden Fermi surface.