Coexistence of superconductivity and antiferromagnetism in self-doped bilayer t-t'-J model

TL;DR

This paper investigates a self-doped bilayer t-t'-J model using slave-boson mean-field theory, revealing coexisting antiferromagnetic and superconducting phases with characteristic Fermi surface features.

Contribution

It demonstrates the coexistence of AFM and superconductivity in a self-doped bilayer model, highlighting the effects of interlayer hopping and electron correlations.

Findings

Coexistence of AFM and superconductivity in the model.

Fermi surfaces show two pockets around nodal and anti-nodal regions.

Absence of FS splitting in the nodal direction due to flat band from AFM order.

Abstract

A self-doped bilayer t-t'-J model of an electron- and a hole-doped planes is studied by the slave-boson mean-field theory. A hopping integral between the differently doped planes, which are generated by a site potential, are renormalized by the electron-electron correlation. We find coexistent phases of antiferromagnetic (AFM) and superconducting orders, although the magnitudes of order parameters become more dissimilar in the bilayer away from half-filling. Fermi surfaces (FS's) with the AFM order show two pockets around the nodal and the anti-nodal regions. These results look like a composite of electron- and hole-doped FS's. In the nodal direction, the FS splitting is absent even in the bilayer system, since one band is flat due to the AFM order.