On the relation between the boson-fermion model and RVB state

TL;DR

This paper demonstrates that the RVB state of the t-J model can be effectively described by a boson-fermion Hamiltonian, revealing a hybridization between holons and spinons, and compares it with phenomenological models of the pseudogap phase.

Contribution

It derives a boson-fermion Hamiltonian from the t-J model that captures the RVB state and its excitations, providing a microscopic foundation for phenomenological BFM approaches.

Findings

The effective Hamiltonian describes holon-spinon coupling.

The RVB order parameter induces hybridization.

Comparison with phenomenological BFM shows consistency.

Abstract

We show that the resonating valence bond (RVB) state of the t-J Hamiltonian can be described within an effective boson-fermion model. We derive a boson-fermion Hamiltonian which describes the lowest order coupling between holons and spinon waves. The RVB order parameter determines a hybridization between the both types of excitations. The effective Hamiltonian is investigated within the lowest order self-consistent conserving diagrammatic approximation. We compare our approach with the phenomenological boson--fermion model (BFM) that is believed to describe the pseudogap phase.