Hubbard Bands and Exotic States in Doped and Undoped Mott Systems: The Kotliar-Ruckenstein Representation

TL;DR

This paper develops a unified slave-particle approach combining Kotliar-Ruckenstein and spin-liquid theories to analyze Mott systems, revealing how magnetic order and doping influence Hubbard bands and Fermi surfaces.

Contribution

It introduces a modified Kotliar-Ruckenstein representation that captures both magnetic order and spin-liquid features in strongly correlated systems.

Findings

The spectrum in the insulating state is affected by spinon spin-liquid features.

Magnetic order influences the formation of Fermi surfaces in doped Mott insulators.

The approach describes the Mott transition and Hubbard subbands within a unified framework.

Abstract

The slave-particle representation is a promising method to treat the properties of exotic strongly correlated systems. We develop a unified approach to describe both the paramagnetic state with possible spin-liquid features and states with strong long-range or short-range magnetic order. Combining the Kotliar-Ruckenstein representation and fractionalized spin-liquid deconfinement picture, the Mott transition and Hubbard subbands are considered. The spectrum in the insulating state is significantly affected by the presence of the spinon spin-liquid spectrum and a hidden Fermi surface. Presenting a modification of the Kotliar-Ruckenstein representation in the spin-wave region, we treat the case of magnetic order, with special attention being paid to the half-metallic ferromagnetic state. The formation of small and large Fermi surfaces for doped current carriers in the antiferromagnetic state is also discussed.