Frustrated Further-Neighbor Antiferromagnetic and Electron-Hopping Interactions in the d=3 tJ Model: Finite-Temperature Global Phase Diagrams from Renormalization-Group Theory

TL;DR

This paper extends the renormalization-group analysis of the three-dimensional tJ model to include further-neighbor interactions, revealing complex phase diagrams with multiple superconducting phases potentially analogous to BEC and BCS types.

Contribution

It introduces a comprehensive renormalization-group framework for the d=3 tJ model with extended interactions, mapping out global phase diagrams across various parameters.

Findings

Identification of the au_{tJ} phase in extended models.

Discovery of the au_{Hb} phase near and away from half-filling.

Potential correspondence of phases to BEC-like and BCS-like superconductivity.

Abstract

The renormalization-group theory of the d=3 tJ model is extended to further-neighbor antiferromagnetic or electron-hopping interactions, including the ranges of frustration. The global phase diagram of each model is calculated for the entire ranges of temperatures, electron densities, and further/first-neighbor interaction strength ratios. In addition to the \tau_{tJ} phase seen in earlier studies of the nearest-neighbor d=3 tJ model, the \tau_{Hb} phase seen before in the d=3 Hubbard model appears both near and away from half-filling. These distinct \tau phases potentially correspond to different (BEC-like and BCS-like) superconducting phases.