Spin texture in a bilayer high-temperature cuprate superconductor

We investigate the possibility of spin texture in the bilayer cuprate superconductor ${\mathrm{Bi}}₂{\mathrm{Sr}}₂{\mathrm{CaCu}}₂{\mathrm{O}}_{8+\ensuremath{\delta}}$ using cluster dynamical mean-field theory. 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 $\mathbf{k}=(\ensuremath{\pi},\ensuremath{\pi})$ and stable against the superconducting phase. We predict that the amplitude of the spin structure is strongly affected by the pseudogap phenomenon, more so than the spectral function itself.