Adiabatic Continuation between Resonating-Valence-Bond Electron and Spin Liquids

TL;DR

This paper demonstrates that in the strong-coupling Hubbard model, the electron liquid stabilized by superexchange is an RVB electron liquid, which is adiabatically connected to the RVB spin liquid in the Heisenberg model, revealing a deep connection between these states.

Contribution

It establishes the adiabatic connection between the RVB electron liquid in the Hubbard model and the RVB spin liquid in the Heisenberg model, clarifying their relationship.

Findings

The electron liquid is stabilized by superexchange in the Hubbard model.

The RVB electron liquid is adiabatically connected to the RVB spin liquid.

No symmetry breaking occurs at low temperatures in low dimensions.

Abstract

The Hubbard model in the strong-coupling regime is studied by the Kondo-lattice theory. If no symmetry is broken at a sufficiently low temperature in sufficiently low dimensions, an electron liquid is stabilized by the Fock-type exchange effect of the superexchange interaction. Since the stabilization mechanism is none other than the resonating-valence-bond (RVB) mechanism, the electron liquid is none other than an RVB electron liquid. The RVB electron liquid in the Hubbard model is adiabatically connected to the RVB spin liquid in the Heisenberg model.