Spin texture in a bilayer high-temperature cuprate superconductor

TL;DR

This study explores spin textures in a bilayer high-temperature cuprate superconductor using advanced theoretical modeling, revealing stable circulating spin patterns influenced by pseudogap phenomena.

Contribution

It introduces a theoretical framework combining Hubbard model, Rashba coupling, and CDMFT to predict spin textures in bilayer cuprates, highlighting effects on the superconducting state.

Findings

Circulating spin textures are stable in the superconducting phase.

Spin amplitude is strongly affected by the pseudogap phenomenon.

The $d$-wave order parameter remains largely unaffected by Rashba coupling.

Abstract

We investigate the possibility of spin texture in the bilayer cuprate superconductor $\rm Bi_2Sr_2CaCu_2O_{8+\delta}$ using cluster dynamical mean field theory (CDMFT). The one-band Hubbard model with a small interlayer hopping and a Rashba spin-orbit coupling is used to describe the material. The $d$-wave order parameter is not much affected by the presence of the Rashba coupling, but a small triplet component appears. We find a spin texture circulating in the same direction around $\mathbf{k}=(0,0)$ and $\mathbf{k}=(\pi,\pi)$ and stable against the superconducting phase. The amplitude of the spin structure, however, is strongly affected by the pseudogap phenomenon, more so than the spectral function itself.